391616520 has 32 divisors (see below), whose sum is σ = 1174849920. Its totient is φ = 104431040.

The previous prime is 391616501. The next prime is 391616527. The reversal of 391616520 is 25616193.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (391616527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1631616 + ... + 1631855.

It is an arithmetic number, because the mean of its divisors is an integer number (36714060).

Almost surely, 2^391616520 is an apocalyptic number.

391616520 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

391616520 is an abundant number, since it is smaller than the sum of its proper divisors (783233400).

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

391616520 is a wasteful number, since it uses less digits than its factorization.

391616520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3263485 (or 3263481 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 391616520 is about 19789.3031711579. The cubic root of 391616520 is about 731.6224126861.

The spelling of 391616520 in words is "three hundred ninety-one million, six hundred sixteen thousand, five hundred twenty".