20800331206661 has 16 divisors (see below), whose sum is σ = 20902726278720. Its totient is φ = 20698205537280.

The previous prime is 20800331206643. The next prime is 20800331206693. The reversal of 20800331206661 is 16660213300802.

It is a cyclic number.

It is not a de Polignac number, because 20800331206661 - 2²² = 20800327012357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20800331206561) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1267454546 + ... + 1267470956.

It is an arithmetic number, because the mean of its divisors is an integer number (1306420392420).

Almost surely, 2^{20800331206661} is an apocalyptic number.

It is an amenable number.

20800331206661 is a deficient number, since it is larger than the sum of its proper divisors (102395072059).

20800331206661 is a wasteful number, since it uses less digits than its factorization.

20800331206661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24244.

The product of its (nonzero) digits is 62208, while the sum is 38.

The spelling of 20800331206661 in words is "twenty trillion, eight hundred billion, three hundred thirty-one million, two hundred six thousand, six hundred sixty-one".