261985960056 has 16 divisors (see below), whose sum is σ = 654964900200. Its totient is φ = 87328653344.

The previous prime is 261985960043. The next prime is 261985960069. The reversal of 261985960056 is 650069589162.

It is an interprime number because it is at equal distance from previous prime (261985960043) and next prime (261985960069).

It is a junction number, because it is equal to n+sod(n) for n = 261985959978 and 261985960005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5458040811 + ... + 5458040858.

Almost surely, 2^261985960056 is an apocalyptic number.

It is an amenable number.

261985960056 is an abundant number, since it is smaller than the sum of its proper divisors (392978940144).

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

261985960056 is a wasteful number, since it uses less digits than its factorization.

261985960056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10916081678 (or 10916081674 counting only the distinct ones).

The product of its (nonzero) digits is 6998400, while the sum is 57.

The spelling of 261985960056 in words is "two hundred sixty-one billion, nine hundred eighty-five million, nine hundred sixty thousand, fifty-six".