31380864 has 64 divisors (see below), whose sum is σ = 84602880. Its totient is φ = 10304000.

The previous prime is 31380859. The next prime is 31380893. The reversal of 31380864 is 46808313.

It is a tau number, because it is divible by the number of its divisors (64).

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 26689 + ... + 27839.

It is an arithmetic number, because the mean of its divisors is an integer number (1321920).

Almost surely, 2^31380864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31380864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42301440).

31380864 is an abundant number, since it is smaller than the sum of its proper divisors (53222016).

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

31380864 is a wasteful number, since it uses less digits than its factorization.

31380864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1239 (or 1227 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 31380864 is about 5601.8625474033. The cubic root of 31380864 is about 315.4193256509.

The spelling of 31380864 in words is "thirty-one million, three hundred eighty thousand, eight hundred sixty-four".