12704639 has 4 divisors (see below), whose sum is σ = 13142760. Its totient is φ = 12266520.

The previous prime is 12704633. The next prime is 12704641. The reversal of 12704639 is 93640721.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12704639 is a prime.

It is a super-2 number, since 2×12704639² = 322815704240642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12704633) 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, 219017 + ... + 219074.

It is an arithmetic number, because the mean of its divisors is an integer number (3285690).

Almost surely, 2^12704639 is an apocalyptic number.

12704639 is a deficient number, since it is larger than the sum of its proper divisors (438121).

12704639 is an equidigital number, since it uses as much as digits as its factorization.

12704639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 438120.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 12704639 is about 3564.3567442107. The cubic root of 12704639 is about 233.3390594967.

The spelling of 12704639 in words is "twelve million, seven hundred four thousand, six hundred thirty-nine".