51865731 has 16 divisors (see below), whose sum is σ = 77269920. Its totient is φ = 34382880.

The previous prime is 51865721. The next prime is 51865739. The reversal of 51865731 is 13756815.

51865731 is a `hidden beast` number, since 5 + 1 + 86 + 573 + 1 = 666.

It is not a de Polignac number, because 51865731 - 2²² = 47671427 is a prime.

It is a super-2 number, since 2×51865731² = 5380108104328722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51865739) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 420 + ... + 10193.

It is an arithmetic number, because the mean of its divisors is an integer number (4829370).

Almost surely, 2^51865731 is an apocalyptic number.

51865731 is a deficient number, since it is larger than the sum of its proper divisors (25404189).

51865731 is a wasteful number, since it uses less digits than its factorization.

51865731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10803 (or 10797 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 51865731 is about 7201.7866533243. The cubic root of 51865731 is about 372.9295820224.

The spelling of 51865731 in words is "fifty-one million, eight hundred sixty-five thousand, seven hundred thirty-one".