64640525 has 12 divisors (see below), whose sum is σ = 80575572. Its totient is φ = 51440640.

The previous prime is 64640503. The next prime is 64640539. The reversal of 64640525 is 52504646.

It can be written as a sum of positive squares in 6 ways, for example, as 19307236 + 45333289 = 4394^2 + 6733^2 .

It is not a de Polignac number, because 64640525 - 2⁸ = 64640269 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64640491 and 64640500.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1874 + ... + 11523.

It is an arithmetic number, because the mean of its divisors is an integer number (6714631).

Almost surely, 2^64640525 is an apocalyptic number.

It is an amenable number.

64640525 is a deficient number, since it is larger than the sum of its proper divisors (15935047).

64640525 is a wasteful number, since it uses less digits than its factorization.

64640525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13600 (or 13595 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 32.

The square root of 64640525 is about 8039.9331464882. The cubic root of 64640525 is about 401.3299999325.

The spelling of 64640525 in words is "sixty-four million, six hundred forty thousand, five hundred twenty-five".