12643664 has 60 divisors (see below), whose sum is σ = 28346400. Its totient is φ = 5417280.

The previous prime is 12643661. The next prime is 12643669. The reversal of 12643664 is 46634621.

It is a super-3 number, since 3×12643664³ (a number of 22 digits) contains 333 as substring.

Its product of digits (20736) is a multiple of the sum of its prime factors (256).

It is a self number, because there is not a number n which added to its sum of digits gives 12643664.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12643661) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 63437 + ... + 63635.

It is an arithmetic number, because the mean of its divisors is an integer number (472440).

Almost surely, 2^12643664 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 12643664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14173200).

12643664 is an abundant number, since it is smaller than the sum of its proper divisors (15702736).

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

12643664 is a wasteful number, since it uses less digits than its factorization.

12643664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256 (or 231 counting only the distinct ones).

The product of its digits is 20736, while the sum is 32.

The square root of 12643664 is about 3555.7930198480. The cubic root of 12643664 is about 232.9651626892.

The spelling of 12643664 in words is "twelve million, six hundred forty-three thousand, six hundred sixty-four".