261322920 has 48 divisors (see below), whose sum is σ = 849300660. Its totient is φ = 69686016.

The previous prime is 261322907. The next prime is 261322933. The reversal of 261322920 is 29223162.

261322920 is a `hidden beast` number, since 2 + 613 + 2 + 29 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (261322907) and next prime (261322933).

It can be written as a sum of positive squares in 2 ways, for example, as 251095716 + 10227204 = 15846^2 + 3198^2 .

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, 362589 + ... + 363308.

Almost surely, 2^261322920 is an apocalyptic number.

261322920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261322920 is an abundant number, since it is smaller than the sum of its proper divisors (587977740).

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

261322920 is a wasteful number, since it uses less digits than its factorization.

261322920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725914 (or 725907 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 261322920 is about 16165.4854551294. The cubic root of 261322920 is about 639.3311045334.

The spelling of 261322920 in words is "two hundred sixty-one million, three hundred twenty-two thousand, nine hundred twenty".