391520256 has 112 divisors (see below), whose sum is σ = 1061618400. Its totient is φ = 128319488.

The previous prime is 391520221. The next prime is 391520257. The reversal of 391520256 is 652025193.

It is a super-2 number, since 2×391520256² = 306576221716611072, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (391520257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2187175 + ... + 2187353.

Almost surely, 2^391520256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 391520256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (530809200).

391520256 is an abundant number, since it is smaller than the sum of its proper divisors (670098144).

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

391520256 is an equidigital number, since it uses as much as digits as its factorization.

391520256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297 (or 273 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 33.

The square root of 391520256 is about 19786.8707985876. The cubic root of 391520256 is about 731.5624606089.

The spelling of 391520256 in words is "three hundred ninety-one million, five hundred twenty thousand, two hundred fifty-six".