51664860 has 72 divisors (see below), whose sum is σ = 168779520. Its totient is φ = 12716928.

The previous prime is 51664859. The next prime is 51664871. The reversal of 51664860 is 6846615.

51664860 is a `hidden beast` number, since 5 + 1 + 6 + 648 + 6 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8700 + ... + 13379.

It is an arithmetic number, because the mean of its divisors is an integer number (2344160).

Almost surely, 2^51664860 is an apocalyptic number.

It is an amenable number.

51664860 is an abundant number, since it is smaller than the sum of its proper divisors (117114660).

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

51664860 is a wasteful number, since it uses less digits than its factorization.

51664860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22107 (or 22102 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 51664860 is about 7187.8272099432. The cubic root of 51664860 is about 372.4475189941.

The spelling of 51664860 in words is "fifty-one million, six hundred sixty-four thousand, eight hundred sixty".