31728715731 has 24 divisors (see below), whose sum is σ = 48613522464. Its totient is φ = 19872418560.

The previous prime is 31728715691. The next prime is 31728715751. The reversal of 31728715731 is 13751782713.

31728715731 is a `hidden beast` number, since 3 + 1 + 7 + 2 + 8 + 71 + 573 + 1 = 666.

It is not a de Polignac number, because 31728715731 - 2¹⁸ = 31728453587 is a prime.

It is a super-2 number, since 2×31728715731² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (31728715751) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 100935 + ... + 271376.

It is an arithmetic number, because the mean of its divisors is an integer number (2025563436).

Almost surely, 2^31728715731 is an apocalyptic number.

31728715731 is a deficient number, since it is larger than the sum of its proper divisors (16884806733).

31728715731 is a wasteful number, since it uses less digits than its factorization.

31728715731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 372891 (or 372888 counting only the distinct ones).

The product of its digits is 246960, while the sum is 45.

The spelling of 31728715731 in words is "thirty-one billion, seven hundred twenty-eight million, seven hundred fifteen thousand, seven hundred thirty-one".