51685632 has 54 divisors (see below), whose sum is σ = 149029062. Its totient is φ = 17227776.

The previous prime is 51685631. The next prime is 51685637. The reversal of 51685632 is 23658615.

51685632 is a `hidden beast` number, since 5 + 16 + 8 + 5 + 632 = 666.

It can be written as a sum of positive squares in only one way, i.e., 50466816 + 1218816 = 7104^2 + 1104^2 .

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (51685631) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8913 + ... + 13520.

Almost surely, 2^51685632 is an apocalyptic number.

It is an amenable number.

51685632 is an abundant number, since it is smaller than the sum of its proper divisors (97343430).

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

51685632 is a wasteful number, since it uses less digits than its factorization.

51685632 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22455 (or 22438 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 51685632 is about 7189.2720076514. The cubic root of 51685632 is about 372.4974268249.

The spelling of 51685632 in words is "fifty-one million, six hundred eighty-five thousand, six hundred thirty-two".