646654625 has 8 divisors (see below), whose sum is σ = 807025128. Its totient is φ = 517323600.

The previous prime is 646654609. The next prime is 646654639. The reversal of 646654625 is 526456646.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1697809 + 644956816 = 1303^2 + 25396^2 .

It is not a de Polignac number, because 646654625 - 2⁴ = 646654609 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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, 2586494 + ... + 2586743.

It is an arithmetic number, because the mean of its divisors is an integer number (100878141).

Almost surely, 2^646654625 is an apocalyptic number.

It is an amenable number.

646654625 is a deficient number, since it is larger than the sum of its proper divisors (160370503).

646654625 is an equidigital number, since it uses as much as digits as its factorization.

646654625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5173252 (or 5173242 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 44.

The square root of 646654625 is about 25429.4047315308. The cubic root of 646654625 is about 864.7504486884.

The spelling of 646654625 in words is "six hundred forty-six million, six hundred fifty-four thousand, six hundred twenty-five".