261256320 has 256 divisors, whose sum is σ = 997315200. Its totient is φ = 64253952.

The previous prime is 261256301. The next prime is 261256337. The reversal of 261256320 is 23652162.

261256320 is a `hidden beast` number, since 2 + 6 + 1 + 25 + 632 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 224059 + ... + 225221.

Almost surely, 2^261256320 is an apocalyptic number.

261256320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261256320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (498657600).

261256320 is an abundant number, since it is smaller than the sum of its proper divisors (736058880).

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

261256320 is a wasteful number, since it uses less digits than its factorization.

261256320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1204 (or 1186 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 261256320 is about 16163.4253795413. The cubic root of 261256320 is about 639.2767872296.

The spelling of 261256320 in words is "two hundred sixty-one million, two hundred fifty-six thousand, three hundred twenty".