12865644 has 72 divisors (see below), whose sum is σ = 36206352. Its totient is φ = 3818880.

The previous prime is 12865631. The next prime is 12865663. The reversal of 12865644 is 44656821.

12865644 is a `hidden beast` number, since 1 + 2 + 8 + 6 + 5 + 644 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 12865599 and 12865608.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20682 + ... + 21294.

It is an arithmetic number, because the mean of its divisors is an integer number (502866).

Almost surely, 2^12865644 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 12865644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18103176).

12865644 is an abundant number, since it is smaller than the sum of its proper divisors (23340708).

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

12865644 is a wasteful number, since it uses less digits than its factorization.

12865644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687 (or 682 counting only the distinct ones).

The product of its digits is 46080, while the sum is 36.

The square root of 12865644 is about 3586.8710598515. The cubic root of 12865644 is about 234.3206211975.

The spelling of 12865644 in words is "twelve million, eight hundred sixty-five thousand, six hundred forty-four".