51978924 has 18 divisors (see below), whose sum is σ = 131391260. Its totient is φ = 17326296.

The previous prime is 51978923. The next prime is 51978929. The reversal of 51978924 is 42987915.

It is a tau number, because it is divible by the number of its divisors (18).

It is a self number, because there is not a number n which added to its sum of digits gives 51978924.

It is not an unprimeable number, because it can be changed into a prime (51978923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 721894 + ... + 721965.

Almost surely, 2^51978924 is an apocalyptic number.

It is an amenable number.

51978924 is an abundant number, since it is smaller than the sum of its proper divisors (79412336).

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

51978924 is a wasteful number, since it uses less digits than its factorization.

51978924 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1443869 (or 1443864 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 51978924 is about 7209.6410451561. The cubic root of 51978924 is about 373.2006816846.

The spelling of 51978924 in words is "fifty-one million, nine hundred seventy-eight thousand, nine hundred twenty-four".