31728957687 has 80 divisors (see below), whose sum is σ = 55302730560. Its totient is φ = 17752670208.

The previous prime is 31728957683. The next prime is 31728957719. The reversal of 31728957687 is 78675982713.

31728957687 is a `hidden beast` number, since 31 + 7 + 28 + 9 + 576 + 8 + 7 = 666.

It is not a de Polignac number, because 31728957687 - 2² = 31728957683 is a prime.

It is a Smith number, since the sum of its digits (63) 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 (63).

Its product of digits (35562240) is a multiple of the sum of its prime divisors (2205).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31728957683) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 23108533 + ... + 23109905.

It is an arithmetic number, because the mean of its divisors is an integer number (691284132).

Almost surely, 2^31728957687 is an apocalyptic number.

31728957687 is a deficient number, since it is larger than the sum of its proper divisors (23573772873).

31728957687 is a wasteful number, since it uses less digits than its factorization.

31728957687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2214 (or 2205 counting only the distinct ones).

The product of its digits is 35562240, while the sum is 63.

The spelling of 31728957687 in words is "thirty-one billion, seven hundred twenty-eight million, nine hundred fifty-seven thousand, six hundred eighty-seven".