51809568 has 48 divisors (see below), whose sum is σ = 139327776. Its totient is φ = 16847360.

The previous prime is 51809533. The next prime is 51809629. The reversal of 51809568 is 86590815.

It is a tau number, because it is divible by the number of its divisors (48).

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, 2646 + ... + 10517.

It is an arithmetic number, because the mean of its divisors is an integer number (2902662).

Almost surely, 2^51809568 is an apocalyptic number.

It is an amenable number.

51809568 is an abundant number, since it is smaller than the sum of its proper divisors (87518208).

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

51809568 is a wasteful number, since it uses less digits than its factorization.

51809568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13217 (or 13209 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 42.

The square root of 51809568 is about 7197.8863564244. The cubic root of 51809568 is about 372.7949240100.

The spelling of 51809568 in words is "fifty-one million, eight hundred nine thousand, five hundred sixty-eight".