12691655278 has 8 divisors (see below), whose sum is σ = 19084030560. Its totient is φ = 6330311760.

The previous prime is 12691655209. The next prime is 12691655281. The reversal of 12691655278 is 87255619621.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×12691655278² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7756918 + ... + 7758553.

It is an arithmetic number, because the mean of its divisors is an integer number (2385503820).

Almost surely, 2^12691655278 is an apocalyptic number.

12691655278 is a deficient number, since it is larger than the sum of its proper divisors (6392375282).

12691655278 is a wasteful number, since it uses less digits than its factorization.

12691655278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15515882.

The product of its digits is 1814400, while the sum is 52.

The spelling of 12691655278 in words is "twelve billion, six hundred ninety-one million, six hundred fifty-five thousand, two hundred seventy-eight".