12666777680 has 20 divisors (see below), whose sum is σ = 29450258292. Its totient is φ = 5066711040.

The previous prime is 12666777547. The next prime is 12666777713. The reversal of 12666777680 is 8677766621.

It can be written as a sum of positive squares in 2 ways, for example, as 4277683216 + 8389094464 = 65404^2 + 91592^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79167281 + ... + 79167440.

Almost surely, 2^12666777680 is an apocalyptic number.

12666777680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12666777680 is an abundant number, since it is smaller than the sum of its proper divisors (16783480612).

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

12666777680 is a wasteful number, since it uses less digits than its factorization.

12666777680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158334734 (or 158334728 counting only the distinct ones).

The product of its (nonzero) digits is 7112448, while the sum is 56.

The spelling of 12666777680 in words is "twelve billion, six hundred sixty-six million, seven hundred seventy-seven thousand, six hundred eighty".