51664816 has 30 divisors (see below), whose sum is σ = 116445300. Its totient is φ = 22141728.

The previous prime is 51664813. The next prime is 51664829. The reversal of 51664816 is 61846615.

It is not an unprimeable number, because it can be changed into a prime (51664813) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 32166 + ... + 33733.

It is an arithmetic number, because the mean of its divisors is an integer number (3881510).

Almost surely, 2^51664816 is an apocalyptic number.

51664816 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

51664816 is an abundant number, since it is smaller than the sum of its proper divisors (64780484).

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

51664816 is a wasteful number, since it uses less digits than its factorization.

51664816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65921 (or 65908 counting only the distinct ones).

The product of its digits is 34560, while the sum is 37.

The square root of 51664816 is about 7187.8241492123. The cubic root of 51664816 is about 372.4474132633.

The spelling of 51664816 in words is "fifty-one million, six hundred sixty-four thousand, eight hundred sixteen".