261379555835904 has 180 divisors, whose sum is σ = 823716497025240. Its totient is φ = 79205925519360.

The previous prime is 261379555835891. The next prime is 261379555835921. The reversal of 261379555835904 is 409538555973162.

261379555835904 is a `hidden beast` number, since 2 + 6 + 1 + 37 + 9 + 5 + 5 + 583 + 5 + 9 + 0 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 78950419 + ... + 82194450.

It is a 1-persistent number, because it is pandigital, but 2⋅261379555835904 = 522759111671808 is not.

Almost surely, 2^{261379555835904} is an apocalyptic number.

261379555835904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

261379555835904 is an abundant number, since it is smaller than the sum of its proper divisors (562336941189336).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261379555835904 is a wasteful number, since it uses less digits than its factorization.

261379555835904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161144914 (or 161144885 counting only the distinct ones).

The product of its (nonzero) digits is 1224720000, while the sum is 72.

The spelling of 261379555835904 in words is "two hundred sixty-one trillion, three hundred seventy-nine billion, five hundred fifty-five million, eight hundred thirty-five thousand, nine hundred four".