31289664 has 112 divisors (see below), whose sum is σ = 97796096. Its totient is φ = 8640000.

The previous prime is 31289627. The next prime is 31289669. The reversal of 31289664 is 46698213.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31289669) 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, 41289 + ... + 42039.

Almost surely, 2^31289664 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 31289664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48898048).

31289664 is an abundant number, since it is smaller than the sum of its proper divisors (66506432).

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

31289664 is a wasteful number, since it uses less digits than its factorization.

31289664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804 (or 794 counting only the distinct ones).

The product of its digits is 62208, while the sum is 39.

The square root of 31289664 is about 5593.7164747599. The cubic root of 31289664 is about 315.1134688217.

The spelling of 31289664 in words is "thirty-one million, two hundred eighty-nine thousand, six hundred sixty-four".