31728765 has 32 divisors (see below), whose sum is σ = 53844480. Its totient is φ = 15909696.

The previous prime is 31728679. The next prime is 31728769. The reversal of 31728765 is 56782713.

It is not a de Polignac number, because 31728765 - 2⁸ = 31728509 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31728769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46114 + ... + 46796.

It is an arithmetic number, because the mean of its divisors is an integer number (1682640).

Almost surely, 2^31728765 is an apocalyptic number.

It is an amenable number.

31728765 is a deficient number, since it is larger than the sum of its proper divisors (22115715).

31728765 is a wasteful number, since it uses less digits than its factorization.

31728765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873.

The product of its digits is 70560, while the sum is 39.

The square root of 31728765 is about 5632.8292180751. The cubic root of 31728765 is about 316.5806667048.

The spelling of 31728765 in words is "thirty-one million, seven hundred twenty-eight thousand, seven hundred sixty-five".