261569513856 has 96 divisors (see below), whose sum is σ = 808229837880. Its totient is φ = 74734141440.

The previous prime is 261569513851. The next prime is 261569513969. The reversal of 261569513856 is 658315965162.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×261569513856² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 261569513796 and 261569513805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261569513851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6931905 + ... + 6969536.

Almost surely, 2^261569513856 is an apocalyptic number.

It is an amenable number.

261569513856 is an abundant number, since it is smaller than the sum of its proper divisors (546660324024).

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

261569513856 is a wasteful number, since it uses less digits than its factorization.

261569513856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13901472 (or 13901453 counting only the distinct ones).

The product of its digits is 11664000, while the sum is 57.

The spelling of 261569513856 in words is "two hundred sixty-one billion, five hundred sixty-nine million, five hundred thirteen thousand, eight hundred fifty-six".