The Bronx Jews are like Tom and Huckleberry at their own funeral: “dead” and mourned, somewhat raggedy, yet more alive than anyone dreamed.

According to the latest UJA-Federation of New York Jewish Community Study, the Northeast and South Bronx — not even counting Riverdale — has more Jewish households than the Five Towns of Long Island; more Jews than North Carolina and South Carolina combined. The borough, with 53,900 Jews, up almost 9,000 since 2002, has more Jews than Houston.

Contrary to the conventional wisdom, more Bronx Jews (33,800) live outside Riverdale than in it (20,100).

And yet, it may be argued that no Jewish community has ever been so invisible, so in the throes of assimilation and alienation, growing yet withering away. Like Huckleberry resisting the civilizing of the Widder Douglas, a vast portion of Bronx Jews outside Riverdale aren’t keen on religion, or anything resembling Jewish community either.

This is a population, says the UJA-Federation study, “characterized by weak or tenuous ties to the Jewish community and Jewish life.” Almost half, 44 percent, say they have no religion at all, or are secular, beyond denomination. The Bronx appears “less Jewishly connected and identified than” the rest of New York City, Westchester and Long Island, reports the study. But it’s getting worse — “it’s overall level of Jewish engagement appears to have weakened considerably since 2002.”

There are around 10 Bronx synagogues outside Riverdale (the number will be inexact, explained one Bronx rabbi, because some synagogues are officially in existence but no longer have scheduled services or anyone to answer their phone). By the most generous estimate, these synagogues have less than 500 dues-paying members combined, out of a possible 33,800 Jews. Perhaps the only secular outpost is the Sholom Aleichem Cultural Center, an old “folkshule,” near Montefiore Hospital.

Over on City Island, the quaint, off-shore community often compared to a New England fishing village, the 70-year-old liberal “shul by the sea” has 100 members, up from 20 several years ago, fueled by Rabbi Shohama Wiener’s platform of outreach “to gays and lesbians, interracial and interfaith families,” being open to musicians (with a shul band), and unique membership open to non-Jews, free High Holy Day services and charming programming, such the annual “blessing of the fleet,” may they “steer clear of the shoals and reefs.” And yet, Rabbi Wiener admits that “less than half” of the shul’s members are from the Bronx. The others travel from Westchester or elsewhere in the city.

The extent of mixed families is illuminated by comparing the Northeast Bronx (such neighborhoods as Mosholu, Fordham, Norwood, Pelham Parkway and Co-op City) to the Five Towns (Woodmere, Lawrence, Hewlett, Cedarhurst, Inwood). There are actually more people living in Jewish households in the Northeast Bronx (29,600) than in the Five Towns (25,800), but only 800 non-Jews live in the Five Towns households compared to 11,300 non-Jews in the Jewish households of the Northeast Bronx.

According to the study, many respondents (outside Riverdale) defined themselves as “partially Jewish,” with “one Jewish parent … households that are biracial or non-white.” A prominent Jewish professional, who asked not to be identified, said, “Now things start to make sense. A Jew marries, or is the child of a Hispanic individual, they would have no problem living in an Hispanic neighborhood,” and similarly biracial or non-white Jews would feel comfortable living in black neighborhoods.

The Bronx Jewish Community Council serves 12,000 people a year, targeting Jews but also serving non-Jews. They run the largest food pantry in the East Bronx. The BJCC — whose funders include UJA-Federation — offers workshops around the borough, in lobbies and laundry rooms, with social workers teaching about community resources.

There’s only one real way to find the lost Jews of the Bronx: “Boots on the ground,” says Rabbi Shmuel Zuckerman, 31, of the Young Israel of Pelham Parkway. “Walk the streets. Almost a day doesn’t go by when I don’t meet another Jew, someone new. Smile at people. That’s the way. When I first got here,” in 2011, “my impression was there were no Jews left in the Bronx. But then I’m walking on Shabbos and simply say to people, ‘Good afternoon,’ and they say back to me, ‘Good Shabbos.’ There are Jews here! They need to know, whether they are paying dues or not, they are part of our family.”

The Young Israel sold its building three years ago and merged with the Pelham Parkway Jewish Center. On a “regular Shabbos,” says the rabbi, “we get around 70 people, more than the 40 two years ago.” A Purim party this past week, he added, brought more than 80 people to the shul.

The Young Israel is offering to subsidize a portion of the rent, or home purchase price, to families moving to Pelham Parkway, where an eruv covers a considerable territory. Several families are already availing themselves of the offer: the shul pays up to 40 percent of annual rent for up to three years or $40,000 toward a home purchase.

Rabbi Levi Shemtov is the Chabad emissary to the Bronx, one of the last “shluchim” sent in 1992 by the rebbe, Menachem Mendel Schneerson, before his final illness.

Rabbi Shemtov leads a shul, day camp and nursery school in Riverdale, but he adds, “It was made very clear to me: ‘You’re not [the emissary] to Riverdale only. You’re responsible for every single Jew in the Bronx. You can’t differentiate. You’re responsible and you have to be there. Every single Jew.’”

Rabbi Shemtov now has three Chabad families working alongside him, one assigned to Russian Jews (5 percent of Bronx Jews), with Rabbi Shemtov handling some of the toughest cases in the South Bronx, every week.

Like Rabbi Zuckerman, his boots are on the ground, and a surprising number of people call him on the phone, looking for help.

None of these people are members of a shul, or have ever met him before. “Most Jews that I come across don’t have friends, don’t have family, don’t have money. Obviously, I’m thinking of bringing Yiddishkeit, but if someone needs food or clothing or a place to stay, I’d never say come to me for the spiritual but for the physical go somewhere else. We don’t discriminate between the physical and the spiritual.”

One day a mother calls, asking him to visit her son in prison. Another day, it’s a family split over whether or not to cremate a deceased relative, a violation of Jewish law. The cost of a funeral was an issue for the family, so Rabbi Shemtov raised the money for a Jewish burial, and helped dig the grave himself.

Another day, a call from a woman whose son was becoming bar mitzvah, and could the rabbi do the bar mitzvah in a nursing home, so the grandmother could see? “I went to the nursing home with the boy, we put on tefillin, we said Shema, I spoke, we sang, we danced, we had food, we had a beautiful one-hour ceremony. The only thing is, we didn’t have a minyan so he was called to the Torah at a different time, but everything else was beautiful.”

Rabbi Shemtov and Rabbi Zuckerman see the possibilities. “There is a strong sense of optimism,” says Rabbi Zuckerman. “I want to let people know that we have survived, and we will survive. We are surviving.”