261157540896 has 144 divisors (see below), whose sum is σ = 898689302784. Its totient is φ = 70227228672.

The previous prime is 261157540883. The next prime is 261157540937. The reversal of 261157540896 is 698045751162.

It is a happy number.

261157540896 is a `hidden beast` number, since 2 + 6 + 1 + 1 + 5 + 7 + 540 + 8 + 96 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×261157540896² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3775800 + ... + 3844343.

It is an arithmetic number, because the mean of its divisors is an integer number (6240897936).

Almost surely, 2^261157540896 is an apocalyptic number.

It is an amenable number.

261157540896 is an abundant number, since it is smaller than the sum of its proper divisors (637531761888).

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

261157540896 is a wasteful number, since it uses less digits than its factorization.

261157540896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7620183 (or 7620172 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The spelling of 261157540896 in words is "two hundred sixty-one billion, one hundred fifty-seven million, five hundred forty thousand, eight hundred ninety-six".