12564661 has 8 divisors (see below), whose sum is σ = 12771200. Its totient is φ = 12359952.

The previous prime is 12564637. The next prime is 12564667. The reversal of 12564661 is 16646521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12564661 - 2¹³ = 12556469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12564667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20191 + ... + 20803.

It is an arithmetic number, because the mean of its divisors is an integer number (1596400).

Almost surely, 2^12564661 is an apocalyptic number.

It is an amenable number.

12564661 is a deficient number, since it is larger than the sum of its proper divisors (206539).

12564661 is a wasteful number, since it uses less digits than its factorization.

12564661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 915.

The product of its digits is 8640, while the sum is 31.

The square root of 12564661 is about 3544.6665569557. Note that the first 3 decimals coincide. The cubic root of 12564661 is about 232.4789266752.

It can be divided in two parts, 12564 and 661, that added together give a square (13225 = 115²).

The spelling of 12564661 in words is "twelve million, five hundred sixty-four thousand, six hundred sixty-one".