51991072 has 24 divisors (see below), whose sum is σ = 116980416. Its totient is φ = 22281792.

The previous prime is 51991007. The next prime is 51991081. The reversal of 51991072 is 27019915.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115828 + ... + 116275.

It is an arithmetic number, because the mean of its divisors is an integer number (4874184).

Almost surely, 2^51991072 is an apocalyptic number.

It is an amenable number.

51991072 is an abundant number, since it is smaller than the sum of its proper divisors (64989344).

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

51991072 is a wasteful number, since it uses less digits than its factorization.

51991072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232120 (or 232112 counting only the distinct ones).

The product of its (nonzero) digits is 5670, while the sum is 34.

The square root of 51991072 is about 7210.4834789354. The cubic root of 51991072 is about 373.2297530106.

The spelling of 51991072 in words is "fifty-one million, nine hundred ninety-one thousand, seventy-two".