261638392 has 16 divisors (see below), whose sum is σ = 494915040. Its totient is φ = 129661056.

The previous prime is 261638387. The next prime is 261638413. The reversal of 261638392 is 293836162.

261638392 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

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, 143808 + ... + 145615.

It is an arithmetic number, because the mean of its divisors is an integer number (30932190).

Almost surely, 2^261638392 is an apocalyptic number.

It is an amenable number.

261638392 is a deficient number, since it is larger than the sum of its proper divisors (233276648).

261638392 is a wasteful number, since it uses less digits than its factorization.

261638392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289542 (or 289538 counting only the distinct ones).

The product of its digits is 93312, while the sum is 40.

The square root of 261638392 is about 16175.2400909538. The cubic root of 261638392 is about 639.5882703360.

The spelling of 261638392 in words is "two hundred sixty-one million, six hundred thirty-eight thousand, three hundred ninety-two".