51909680 has 20 divisors (see below), whose sum is σ = 120690192. Its totient is φ = 20763840.

The previous prime is 51909673. The next prime is 51909703. The reversal of 51909680 is 8690915.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×51909680² = 5389229755404800, 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, 324356 + ... + 324515.

Almost surely, 2^51909680 is an apocalyptic number.

It is an amenable number.

51909680 is an abundant number, since it is smaller than the sum of its proper divisors (68780512).

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

51909680 is a wasteful number, since it uses less digits than its factorization.

51909680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648884 (or 648878 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 38.

The square root of 51909680 is about 7204.8372639498. The cubic root of 51909680 is about 373.0348876174.

The spelling of 51909680 in words is "fifty-one million, nine hundred nine thousand, six hundred eighty".