646758625 has 16 divisors (see below), whose sum is σ = 854637264. Its totient is φ = 486969600.

The previous prime is 646758577. The next prime is 646758691. The reversal of 646758625 is 526857646.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 27793984 + 618964641 = 5272^2 + 24879^2 .

It is not a de Polignac number, because 646758625 - 2¹¹ = 646756577 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 150054 + ... + 154303.

It is an arithmetic number, because the mean of its divisors is an integer number (53414829).

Almost surely, 2^646758625 is an apocalyptic number.

It is an amenable number.

646758625 is a deficient number, since it is larger than the sum of its proper divisors (207878639).

646758625 is a wasteful number, since it uses less digits than its factorization.

646758625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304389 (or 304379 counting only the distinct ones).

The product of its digits is 2419200, while the sum is 49.

The square root of 646758625 is about 25431.4495261281. The cubic root of 646758625 is about 864.7968048227.

The spelling of 646758625 in words is "six hundred forty-six million, seven hundred fifty-eight thousand, six hundred twenty-five".