664161925 has 36 divisors (see below), whose sum is σ = 960908736. Its totient is φ = 454053600.

The previous prime is 664161913. The next prime is 664161931. The reversal of 664161925 is 529161466.

It is a happy number.

664161925 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 664161925 - 2⁵ = 664161893 is a prime.

It is a super-2 number, since 2×664161925² = 882222125239411250, which contains 22 as substring.

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 35 ways as a sum of consecutive naturals, for example, 566590 + ... + 567760.

Almost surely, 2^664161925 is an apocalyptic number.

It is an amenable number.

664161925 is a deficient number, since it is larger than the sum of its proper divisors (296746811).

664161925 is a wasteful number, since it uses less digits than its factorization.

664161925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1658 (or 1646 counting only the distinct ones).

The product of its digits is 77760, while the sum is 40.

The square root of 664161925 is about 25771.3392162689. The cubic root of 664161925 is about 872.4850450224.

The spelling of 664161925 in words is "six hundred sixty-four million, one hundred sixty-one thousand, nine hundred twenty-five".