12556661 has 8 divisors (see below), whose sum is σ = 13810944. Its totient is φ = 11343600.

The previous prime is 12556639. The next prime is 12556669. The reversal of 12556661 is 16665521.

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 12556661 - 2²² = 8362357 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 (12556669) 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, 9665 + ... + 10886.

It is an arithmetic number, because the mean of its divisors is an integer number (1726368).

Almost surely, 2^12556661 is an apocalyptic number.

It is an amenable number.

12556661 is a deficient number, since it is larger than the sum of its proper divisors (1254283).

12556661 is a wasteful number, since it uses less digits than its factorization.

12556661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20611.

The product of its digits is 10800, while the sum is 32.

The square root of 12556661 is about 3543.5379213436. The cubic root of 12556661 is about 232.4295759267.

The spelling of 12556661 in words is "twelve million, five hundred fifty-six thousand, six hundred sixty-one".