20371866691 has 32 divisors (see below), whose sum is σ = 22892583168. Its totient is φ = 17972720640.

The previous prime is 20371866661. The next prime is 20371866707. The reversal of 20371866691 is 19666817302.

It is a cyclic number.

It is not a de Polignac number, because 20371866691 - 2⁷ = 20371866563 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20371866661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22460260 + ... + 22461166.

It is an arithmetic number, because the mean of its divisors is an integer number (715393224).

Almost surely, 2^20371866691 is an apocalyptic number.

20371866691 is a deficient number, since it is larger than the sum of its proper divisors (2520716477).

20371866691 is a wasteful number, since it uses less digits than its factorization.

20371866691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1411.

The product of its (nonzero) digits is 653184, while the sum is 49.

The spelling of 20371866691 in words is "twenty billion, three hundred seventy-one million, eight hundred sixty-six thousand, six hundred ninety-one".