664251025 has 6 divisors (see below), whose sum is σ = 823671302. Its totient is φ = 531400800.

The previous prime is 664251019. The next prime is 664251037. The reversal of 664251025 is 520152466.

It can be written as a sum of positive squares in 3 ways, for example, as 114254721 + 549996304 = 10689^2 + 23452^2 .

It is not a de Polignac number, because 664251025 - 2⁷ = 664250897 is a prime.

It is a Duffinian 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, 13284996 + ... + 13285045.

Almost surely, 2^664251025 is an apocalyptic number.

It is an amenable number.

664251025 is a deficient number, since it is larger than the sum of its proper divisors (159420277).

664251025 is a wasteful number, since it uses less digits than its factorization.

664251025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26570051 (or 26570046 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 664251025 is about 25773.0678228262. The cubic root of 664251025 is about 872.5240590734.

The spelling of 664251025 in words is "six hundred sixty-four million, two hundred fifty-one thousand, twenty-five".