51664320 has 84 divisors (see below), whose sum is σ = 177713640. Its totient is φ = 13776384.

The previous prime is 51664273. The next prime is 51664331. The reversal of 51664320 is 2346615.

51664320 is a `hidden beast` number, since 5 + 16 + 643 + 2 + 0 = 666.

It is a super-2 number, since 2×51664320² = 5338403922124800, which contains 22 as substring.

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, 6090 + ... + 11849.

Almost surely, 2^51664320 is an apocalyptic number.

It is an amenable number.

51664320 is an abundant number, since it is smaller than the sum of its proper divisors (126049320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51664320 is a wasteful number, since it uses less digits than its factorization.

51664320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17962 (or 17949 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 51664320 is about 7187.7896463377. The cubic root of 51664320 is about 372.4462213851.

It can be divided in two parts, 51664 and 320, that added together give a square (51984 = 228²).

The spelling of 51664320 in words is "fifty-one million, six hundred sixty-four thousand, three hundred twenty".