12138879690 has 48 divisors (see below), whose sum is σ = 36069815808. Its totient is φ = 2774600928.

The previous prime is 12138879689. The next prime is 12138879713. The reversal of 12138879690 is 9697883121.

It is a super-2 number, since 2×12138879690² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9633402 + ... + 9634661.

It is an arithmetic number, because the mean of its divisors is an integer number (751454496).

Almost surely, 2^12138879690 is an apocalyptic number.

12138879690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

12138879690 is an abundant number, since it is smaller than the sum of its proper divisors (23930936118).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12138879690 is a wasteful number, since it uses less digits than its factorization.

12138879690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19268083 (or 19268080 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 54.

The spelling of 12138879690 in words is "twelve billion, one hundred thirty-eight million, eight hundred seventy-nine thousand, six hundred ninety".