646644325 has 6 divisors (see below), whose sum is σ = 801838994. Its totient is φ = 517315440.

The previous prime is 646644253. The next prime is 646644337. The reversal of 646644325 is 523446646.

It can be written as a sum of positive squares in 3 ways, for example, as 80299521 + 566344804 = 8961^2 + 23798^2 .

It is not a de Polignac number, because 646644325 - 2¹⁵ = 646611557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12932862 + ... + 12932911.

Almost surely, 2^646644325 is an apocalyptic number.

It is an amenable number.

646644325 is a deficient number, since it is larger than the sum of its proper divisors (155194669).

646644325 is a wasteful number, since it uses less digits than its factorization.

646644325 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25865783 (or 25865778 counting only the distinct ones).

The product of its digits is 414720, while the sum is 40.

The square root of 646644325 is about 25429.2022092711. The cubic root of 646644325 is about 864.7458573777.

The spelling of 646644325 in words is "six hundred forty-six million, six hundred forty-four thousand, three hundred twenty-five".