12766639 has 2 divisors, whose sum is σ = 12766640. Its totient is φ = 12766638.

The previous prime is 12766603. The next prime is 12766667. The reversal of 12766639 is 93666721.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12766639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12766669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6383319 + 6383320.

It is an arithmetic number, because the mean of its divisors is an integer number (6383320).

Almost surely, 2^12766639 is an apocalyptic number.

12766639 is a deficient number, since it is larger than the sum of its proper divisors (1).

12766639 is an equidigital number, since it uses as much as digits as its factorization.

12766639 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 40.

The square root of 12766639 is about 3573.0433806491. The cubic root of 12766639 is about 233.7180169191.

It can be divided in two parts, 127 and 66639, that added together give a palindrome (66766).

The spelling of 12766639 in words is "twelve million, seven hundred sixty-six thousand, six hundred thirty-nine".