12739681 has 4 divisors (see below), whose sum is σ = 13489092. Its totient is φ = 11990272.

The previous prime is 12739673. The next prime is 12739687. The reversal of 12739681 is 18693721.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11451456 + 1288225 = 3384^2 + 1135^2 .

It is a cyclic number.

It is not a de Polignac number, because 12739681 - 2³ = 12739673 is a prime.

It is a super-2 number, since 2×12739681² = 324598943963522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12739681.

It is not an unprimeable number, because it can be changed into a prime (12739687) 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, 374680 + ... + 374713.

It is an arithmetic number, because the mean of its divisors is an integer number (3372273).

Almost surely, 2^12739681 is an apocalyptic number.

It is an amenable number.

12739681 is a deficient number, since it is larger than the sum of its proper divisors (749411).

12739681 is an equidigital number, since it uses as much as digits as its factorization.

12739681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 749410.

The product of its digits is 18144, while the sum is 37.

The square root of 12739681 is about 3569.2689727730. The cubic root of 12739681 is about 233.5533948844.

The spelling of 12739681 in words is "twelve million, seven hundred thirty-nine thousand, six hundred eighty-one".