261637126790 has 32 divisors (see below), whose sum is σ = 514121108256. Its totient is φ = 95281125120.

The previous prime is 261637126721. The next prime is 261637126801. The reversal of 261637126790 is 97621736162.

It is a super-2 number, since 2×261637126790² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13775396 + ... + 13794375.

It is an arithmetic number, because the mean of its divisors is an integer number (16066284633).

Almost surely, 2^261637126790 is an apocalyptic number.

261637126790 is a deficient number, since it is larger than the sum of its proper divisors (252483981466).

261637126790 is a wasteful number, since it uses less digits than its factorization.

261637126790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27569864.

The product of its (nonzero) digits is 1143072, while the sum is 50.

The spelling of 261637126790 in words is "two hundred sixty-one billion, six hundred thirty-seven million, one hundred twenty-six thousand, seven hundred ninety".