261556404 has 48 divisors (see below), whose sum is σ = 633931200. Its totient is φ = 83863296.

The previous prime is 261556397. The next prime is 261556433. The reversal of 261556404 is 404655162.

261556404 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×261556404² = 136823504946822432, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36207 + ... + 42825.

It is an arithmetic number, because the mean of its divisors is an integer number (13206900).

Almost surely, 2^261556404 is an apocalyptic number.

It is an amenable number.

261556404 is an abundant number, since it is smaller than the sum of its proper divisors (372374796).

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

261556404 is a wasteful number, since it uses less digits than its factorization.

261556404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6752 (or 6750 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 33.

The square root of 261556404 is about 16172.7055250505. The cubic root of 261556404 is about 639.5214554200.

The spelling of 261556404 in words is "two hundred sixty-one million, five hundred fifty-six thousand, four hundred four".