12138879689 has 2 divisors, whose sum is σ = 12138879690. Its totient is φ = 12138879688.

The previous prime is 12138879677. The next prime is 12138879713. The reversal of 12138879689 is 98697883121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10351027600 + 1787852089 = 101740^2 + 42283^2 .

It is a cyclic number.

It is not a de Polignac number, because 12138879689 - 2¹⁶ = 12138814153 is a prime.

It is not a weakly prime, because it can be changed into another prime (12138879289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6069439844 + 6069439845.

It is an arithmetic number, because the mean of its divisors is an integer number (6069439845).

Almost surely, 2^12138879689 is an apocalyptic number.

It is an amenable number.

12138879689 is a deficient number, since it is larger than the sum of its proper divisors (1).

12138879689 is an equidigital number, since it uses as much as digits as its factorization.

12138879689 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10450944, while the sum is 62.

The spelling of 12138879689 in words is "twelve billion, one hundred thirty-eight million, eight hundred seventy-nine thousand, six hundred eighty-nine".