12638768929 has 4 divisors (see below), whose sum is σ = 12640743700. Its totient is φ = 12636794160.

The previous prime is 12638768921. The next prime is 12638768977. The reversal of 12638768929 is 92986783621.

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 5126560000 + 7512208929 = 71600^2 + 86673^2 .

It is a cyclic number.

It is not a de Polignac number, because 12638768929 - 2³ = 12638768921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12638768921) 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, 977754 + ... + 990595.

It is an arithmetic number, because the mean of its divisors is an integer number (3160185925).

Almost surely, 2^12638768929 is an apocalyptic number.

It is an amenable number.

12638768929 is a deficient number, since it is larger than the sum of its proper divisors (1974771).

12638768929 is an equidigital number, since it uses as much as digits as its factorization.

12638768929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1974770.

The product of its digits is 15676416, while the sum is 61.

The spelling of 12638768929 in words is "twelve billion, six hundred thirty-eight million, seven hundred sixty-eight thousand, nine hundred twenty-nine".