261855904 has 24 divisors (see below), whose sum is σ = 518822388. Its totient is φ = 130091520.

The previous prime is 261855887. The next prime is 261855911. The reversal of 261855904 is 409558162.

It can be written as a sum of positive squares in 2 ways, for example, as 261792400 + 63504 = 16180^2 + 252^2 .

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, 21037 + ... + 31084.

Almost surely, 2^261855904 is an apocalyptic number.

It is an amenable number.

261855904 is a deficient number, since it is larger than the sum of its proper divisors (256966484).

261855904 is a wasteful number, since it uses less digits than its factorization.

261855904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52288 (or 52280 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 40.

The square root of 261855904 is about 16181.9623037504. The cubic root of 261855904 is about 639.7654609346.

The spelling of 261855904 in words is "two hundred sixty-one million, eight hundred fifty-five thousand, nine hundred four".