51809968 has 20 divisors (see below), whose sum is σ = 114722320. Its totient is φ = 22204224.

The previous prime is 51809929. The next prime is 51809971. The reversal of 51809968 is 86990815.

It is a super-2 number, since 2×51809968² = 5368545568322048, which contains 22 as substring.

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, 231183 + ... + 231406.

It is an arithmetic number, because the mean of its divisors is an integer number (5736116).

Almost surely, 2^51809968 is an apocalyptic number.

It is an amenable number.

51809968 is an abundant number, since it is smaller than the sum of its proper divisors (62912352).

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

51809968 is a wasteful number, since it uses less digits than its factorization.

51809968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462604 (or 462598 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 46.

The square root of 51809968 is about 7197.9141423054. The cubic root of 51809968 is about 372.7958834055.

The spelling of 51809968 in words is "fifty-one million, eight hundred nine thousand, nine hundred sixty-eight".