51637644 has 36 divisors (see below), whose sum is σ = 134059744. Its totient is φ = 16746912.

The previous prime is 51637633. The next prime is 51637667. The reversal of 51637644 is 44673615.

It is a happy number.

51637644 is a `hidden beast` number, since 5 + 1 + 6 + 3 + 7 + 644 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 51637599 and 51637608.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18052 + ... + 20715.

Almost surely, 2^51637644 is an apocalyptic number.

It is an amenable number.

51637644 is an abundant number, since it is smaller than the sum of its proper divisors (82422100).

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

51637644 is a wasteful number, since it uses less digits than its factorization.

51637644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38814 (or 38809 counting only the distinct ones).

The product of its digits is 60480, while the sum is 36.

The square root of 51637644 is about 7185.9337597838. The cubic root of 51637644 is about 372.3821082416.

The spelling of 51637644 in words is "fifty-one million, six hundred thirty-seven thousand, six hundred forty-four".