261569023856 has 60 divisors (see below), whose sum is σ = 624209543568. Its totient is φ = 105506827776.

The previous prime is 261569023847. The next prime is 261569023867. The reversal of 261569023856 is 658320965162.

It is a junction number, because it is equal to n+sod(n) for n = 261569023798 and 261569023807.

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, 9799436 + ... + 9826091.

Almost surely, 2^261569023856 is an apocalyptic number.

It is an amenable number.

261569023856 is an abundant number, since it is smaller than the sum of its proper divisors (362640519712).

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

261569023856 is a wasteful number, since it uses less digits than its factorization.

261569023856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19625566 (or 19625553 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 53.

The spelling of 261569023856 in words is "two hundred sixty-one billion, five hundred sixty-nine million, twenty-three thousand, eight hundred fifty-six".