2166136643556 has 36 divisors (see below), whose sum is σ = 5475581110272. Its totient is φ = 722036443824.

The previous prime is 2166136643527. The next prime is 2166136643563. The reversal of 2166136643556 is 6553466316612.

2166136643556 is a `hidden beast` number, since 2 + 16 + 6 + 1 + 36 + 6 + 43 + 556 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2905045 + ... + 3573731.

Almost surely, 2^{2166136643556} is an apocalyptic number.

It is an amenable number.

2166136643556 is an abundant number, since it is smaller than the sum of its proper divisors (3309444466716).

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

2166136643556 is a wasteful number, since it uses less digits than its factorization.

2166136643556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758680 (or 758675 counting only the distinct ones).

The product of its digits is 13996800, while the sum is 54.

The spelling of 2166136643556 in words is "two trillion, one hundred sixty-six billion, one hundred thirty-six million, six hundred forty-three thousand, five hundred fifty-six".