664635525 has 12 divisors (see below), whose sum is σ = 1098864192. Its totient is φ = 354472240.

The previous prime is 664635493. The next prime is 664635527. The reversal of 664635525 is 525536466.

It is not a de Polignac number, because 664635525 - 2⁵ = 664635493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664635527) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4430829 + ... + 4430978.

It is an arithmetic number, because the mean of its divisors is an integer number (91572016).

Almost surely, 2^664635525 is an apocalyptic number.

It is an amenable number.

664635525 is a deficient number, since it is larger than the sum of its proper divisors (434228667).

664635525 is a wasteful number, since it uses less digits than its factorization.

664635525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8861820 (or 8861815 counting only the distinct ones).

The product of its digits is 648000, while the sum is 42.

The square root of 664635525 is about 25780.5260807455. The cubic root of 664635525 is about 872.6923793706.

The spelling of 664635525 in words is "six hundred sixty-four million, six hundred thirty-five thousand, five hundred twenty-five".