51591972 has 48 divisors (see below), whose sum is σ = 122931200. Its totient is φ = 16837632.

The previous prime is 51591971. The next prime is 51591997. The reversal of 51591972 is 27919515.

It is a self number, because there is not a number n which added to its sum of digits gives 51591972.

It is not an unprimeable number, because it can be changed into a prime (51591971) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 147654 + ... + 148002.

Almost surely, 2^51591972 is an apocalyptic number.

It is an amenable number.

51591972 is an abundant number, since it is smaller than the sum of its proper divisors (71339228).

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

51591972 is a wasteful number, since it uses less digits than its factorization.

51591972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580 (or 578 counting only the distinct ones).

The product of its digits is 28350, while the sum is 39.

The square root of 51591972 is about 7182.7551816834. The cubic root of 51591972 is about 372.2722887960.

The spelling of 51591972 in words is "fifty-one million, five hundred ninety-one thousand, nine hundred seventy-two".