646985125 has 16 divisors (see below), whose sum is σ = 827137584. Its totient is φ = 504960000.

The previous prime is 646985113. The next prime is 646985149. The reversal of 646985125 is 521589646.

It can be written as a sum of positive squares in 8 ways, for example, as 545035716 + 101949409 = 23346^2 + 10097^2 .

It is not a de Polignac number, because 646985125 - 2¹³ = 646976933 is a prime.

It is a Duffinian number.

It is a congruent 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 15 ways as a sum of consecutive naturals, for example, 57996 + ... + 68245.

It is an arithmetic number, because the mean of its divisors is an integer number (51696099).

Almost surely, 2^646985125 is an apocalyptic number.

It is an amenable number.

646985125 is a deficient number, since it is larger than the sum of its proper divisors (180152459).

646985125 is a wasteful number, since it uses less digits than its factorization.

646985125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126297 (or 126287 counting only the distinct ones).

The product of its digits is 518400, while the sum is 46.

The square root of 646985125 is about 25435.9022839765. The cubic root of 646985125 is about 864.8977459401.

The spelling of 646985125 in words is "six hundred forty-six million, nine hundred eighty-five thousand, one hundred twenty-five".