12556621 has 16 divisors (see below), whose sum is σ = 15735168. Its totient is φ = 9734400.

The previous prime is 12556613. The next prime is 12556631. The reversal of 12556621 is 12665521.

It is a cyclic number.

It is not a de Polignac number, because 12556621 - 2³ = 12556613 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12556621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12556631) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23841 + ... + 24361.

It is an arithmetic number, because the mean of its divisors is an integer number (983448).

Almost surely, 2^12556621 is an apocalyptic number.

12556621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12556621 is a deficient number, since it is larger than the sum of its proper divisors (3178547).

12556621 is a wasteful number, since it uses less digits than its factorization.

12556621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 852.

The product of its digits is 3600, while the sum is 28.

The square root of 12556621 is about 3543.5322772623. The cubic root of 12556621 is about 232.4293291203.

Subtracting 12556621 from its reverse (12665521), we obtain a square (108900 = 330²).

The spelling of 12556621 in words is "twelve million, five hundred fifty-six thousand, six hundred twenty-one".