261538928 has 40 divisors (see below), whose sum is σ = 580567008. Its totient is φ = 111808512.

The previous prime is 261538919. The next prime is 261538951. The reversal of 261538928 is 829835162.

261538928 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 2×261538928² = 136805221718778368, 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 7 ways as a sum of consecutive naturals, for example, 45800 + ... + 51192.

Almost surely, 2^261538928 is an apocalyptic number.

261538928 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

261538928 is an abundant number, since it is smaller than the sum of its proper divisors (319028080).

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

261538928 is a wasteful number, since it uses less digits than its factorization.

261538928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5841 (or 5835 counting only the distinct ones).

The product of its digits is 207360, while the sum is 44.

The square root of 261538928 is about 16172.1652229997. The cubic root of 261538928 is about 639.5072118054.

The spelling of 261538928 in words is "two hundred sixty-one million, five hundred thirty-eight thousand, nine hundred twenty-eight".