12639641 has 4 divisors (see below), whose sum is σ = 14445312. Its totient is φ = 10833972.

The previous prime is 12639637. The next prime is 12639659. The reversal of 12639641 is 14693621.

12639641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12639641 - 2² = 12639637 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12639598 and 12639607.

It is not an unprimeable number, because it can be changed into a prime (12639941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 902825 + ... + 902838.

It is an arithmetic number, because the mean of its divisors is an integer number (3611328).

Almost surely, 2^12639641 is an apocalyptic number.

It is an amenable number.

12639641 is a deficient number, since it is larger than the sum of its proper divisors (1805671).

12639641 is an equidigital number, since it uses as much as digits as its factorization.

12639641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1805670.

The product of its digits is 7776, while the sum is 32.

The square root of 12639641 is about 3555.2272782482. The cubic root of 12639641 is about 232.9404515436.

The spelling of 12639641 in words is "twelve million, six hundred thirty-nine thousand, six hundred forty-one".