12405621 has 16 divisors (see below), whose sum is σ = 16934400. Its totient is φ = 8076288.

The previous prime is 12405587. The next prime is 12405623. The reversal of 12405621 is 12650421.

12405621 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12405621 - 2⁶ = 12405557 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12405623) 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, 25660 + ... + 26138.

It is an arithmetic number, because the mean of its divisors is an integer number (1058400).

Almost surely, 2^12405621 is an apocalyptic number.

It is an amenable number.

12405621 is a deficient number, since it is larger than the sum of its proper divisors (4528779).

12405621 is an equidigital number, since it uses as much as digits as its factorization.

12405621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 12405621 is about 3522.1614102707. The cubic root of 12405621 is about 231.4938741077.

The spelling of 12405621 in words is "twelve million, four hundred five thousand, six hundred twenty-one".