15640664 has 32 divisors (see below), whose sum is σ = 32130000. Its totient is φ = 7093632.

The previous prime is 15640649. The next prime is 15640687. The reversal of 15640664 is 46604651.

15640664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 15640664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4862 + ... + 7410.

Almost surely, 2^15640664 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 15640664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16065000).

15640664 is an abundant number, since it is smaller than the sum of its proper divisors (16489336).

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

15640664 is a wasteful number, since it uses less digits than its factorization.

15640664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2627 (or 2623 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 15640664 is about 3954.8279355744. The cubic root of 15640664 is about 250.0835134323.

The spelling of 15640664 in words is "fifteen million, six hundred forty thousand, six hundred sixty-four".