646520831 has 16 divisors (see below), whose sum is σ = 718502400. Its totient is φ = 576840000.

The previous prime is 646520807. The next prime is 646520839. The reversal of 646520831 is 138025646.

It is not a de Polignac number, because 646520831 - 2¹⁰ = 646519807 is a prime.

It is a super-2 number, since 2×646520831² = 835978369833861122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 646520791 and 646520800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646520839) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133706 + ... + 138456.

It is an arithmetic number, because the mean of its divisors is an integer number (44906400).

Almost surely, 2^646520831 is an apocalyptic number.

646520831 is a deficient number, since it is larger than the sum of its proper divisors (71981569).

646520831 is a wasteful number, since it uses less digits than its factorization.

646520831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4990.

The product of its (nonzero) digits is 34560, while the sum is 35.

The square root of 646520831 is about 25426.7739007527. The cubic root of 646520831 is about 864.6908051026.

The spelling of 646520831 in words is "six hundred forty-six million, five hundred twenty thousand, eight hundred thirty-one".