2166070072721 has 8 divisors (see below), whose sum is σ = 2195852902824. Its totient is φ = 2136290232960.

The previous prime is 2166070072679. The next prime is 2166070072739. The reversal of 2166070072721 is 1272700706612.

It can be written as a sum of positive squares in 4 ways, for example, as 396874800400 + 1769195272321 = 629980^2 + 1330111^2 .

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 2166070072721 - 2⁶ = 2166070072657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2166070075721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 731051 + ... + 2206031.

It is an arithmetic number, because the mean of its divisors is an integer number (274481612853).

Almost surely, 2^{2166070072721} is an apocalyptic number.

It is an amenable number.

2166070072721 is a deficient number, since it is larger than the sum of its proper divisors (29782830103).

2166070072721 is a wasteful number, since it uses less digits than its factorization.

2166070072721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1495171.

The product of its (nonzero) digits is 98784, while the sum is 41.

The spelling of 2166070072721 in words is "two trillion, one hundred sixty-six billion, seventy million, seventy-two thousand, seven hundred twenty-one".