12643641 has 16 divisors (see below), whose sum is σ = 19051200. Its totient is φ = 8285184.

The previous prime is 12643619. The next prime is 12643643. The reversal of 12643641 is 14634621.

12643641 is a `hidden beast` number, since 12 + 6 + 4 + 3 + 641 = 666.

12643641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 12643641 - 2⁷ = 12643513 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (12643643) 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, 2376 + ... + 5561.

It is an arithmetic number, because the mean of its divisors is an integer number (1190700).

Almost surely, 2^12643641 is an apocalyptic number.

It is an amenable number.

12643641 is a deficient number, since it is larger than the sum of its proper divisors (6407559).

12643641 is an equidigital number, since it uses as much as digits as its factorization.

12643641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8005 (or 7999 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 12643641 is about 3555.7897856876. The cubic root of 12643641 is about 232.9650214274.

The spelling of 12643641 in words is "twelve million, six hundred forty-three thousand, six hundred forty-one".