51219918 has 16 divisors (see below), whose sum is σ = 113822160. Its totient is φ = 17073288.

The previous prime is 51219901. The next prime is 51219983. The reversal of 51219918 is 81991215.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 474205 + ... + 474312.

It is an arithmetic number, because the mean of its divisors is an integer number (7113885).

Almost surely, 2^51219918 is an apocalyptic number.

51219918 is an abundant number, since it is smaller than the sum of its proper divisors (62602242).

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

51219918 is a wasteful number, since it uses less digits than its factorization.

51219918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 948528 (or 948522 counting only the distinct ones).

The product of its digits is 6480, while the sum is 36.

The square root of 51219918 is about 7156.8092052255. The cubic root of 51219918 is about 371.3752520955.

The spelling of 51219918 in words is "fifty-one million, two hundred nineteen thousand, nine hundred eighteen".