12688649 has 2 divisors, whose sum is σ = 12688650. Its totient is φ = 12688648.

The previous prime is 12688609. The next prime is 12688679. The reversal of 12688649 is 94688621.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6538249 + 6150400 = 2557^2 + 2480^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12688649 is a prime.

It is a super-2 number, since 2×12688649² = 322003626890402, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (12688609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6344324 + 6344325.

It is an arithmetic number, because the mean of its divisors is an integer number (6344325).

Almost surely, 2^12688649 is an apocalyptic number.

It is an amenable number.

12688649 is a deficient number, since it is larger than the sum of its proper divisors (1).

12688649 is an equidigital number, since it uses as much as digits as its factorization.

12688649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 165888, while the sum is 44.

The square root of 12688649 is about 3562.1129965233. The cubic root of 12688649 is about 233.2411252442.

The spelling of 12688649 in words is "twelve million, six hundred eighty-eight thousand, six hundred forty-nine".