51861972 has 12 divisors (see below), whose sum is σ = 121011296. Its totient is φ = 17287320.

The previous prime is 51861961. The next prime is 51862067. The reversal of 51861972 is 27916815.

It is a tau number, because it is divible by the number of its divisors (12).

It is a self number, because there is not a number n which added to its sum of digits gives 51861972.

It is a congruent number.

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, 2160904 + ... + 2160927.

Almost surely, 2^51861972 is an apocalyptic number.

It is an amenable number.

51861972 is an abundant number, since it is smaller than the sum of its proper divisors (69149324).

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

51861972 is a wasteful number, since it uses less digits than its factorization.

51861972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4321838 (or 4321836 counting only the distinct ones).

The product of its digits is 30240, while the sum is 39.

The square root of 51861972 is about 7201.5256716893. The cubic root of 51861972 is about 372.9205723729.

The spelling of 51861972 in words is "fifty-one million, eight hundred sixty-one thousand, nine hundred seventy-two".