12776661556 has 24 divisors (see below), whose sum is σ = 22487238144. Its totient is φ = 6351769920.

The previous prime is 12776661539. The next prime is 12776661577. The reversal of 12776661556 is 65516667721.

It is a super-2 number, since 2×12776661556² (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 7 ways as a sum of consecutive naturals, for example, 2926231 + ... + 2930593.

It is an arithmetic number, because the mean of its divisors is an integer number (936968256).

Almost surely, 2^12776661556 is an apocalyptic number.

It is an amenable number.

12776661556 is a deficient number, since it is larger than the sum of its proper divisors (9710576588).

12776661556 is a wasteful number, since it uses less digits than its factorization.

12776661556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8391 (or 8389 counting only the distinct ones).

The product of its digits is 3175200, while the sum is 52.

The spelling of 12776661556 in words is "twelve billion, seven hundred seventy-six million, six hundred sixty-one thousand, five hundred fifty-six".