12564781655 has 8 divisors (see below), whose sum is σ = 15090175392. Its totient is φ = 10043533728.

The previous prime is 12564781637. The next prime is 12564781667. The reversal of 12564781655 is 55618746521.

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

It is a cyclic number.

It is not a de Polignac number, because 12564781655 - 2²⁰ = 12563733079 is a prime.

It is a Duffinian number.

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, 1029779 + ... + 1041908.

It is an arithmetic number, because the mean of its divisors is an integer number (1886271924).

Almost surely, 2^12564781655 is an apocalyptic number.

12564781655 is a deficient number, since it is larger than the sum of its proper divisors (2525393737).

12564781655 is a wasteful number, since it uses less digits than its factorization.

12564781655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2072905.

The product of its digits is 2016000, while the sum is 50.

The spelling of 12564781655 in words is "twelve billion, five hundred sixty-four million, seven hundred eighty-one thousand, six hundred fifty-five".