20811866308790 has 64 divisors (see below), whose sum is σ = 38876892088320. Its totient is φ = 8013133413120.

The previous prime is 20811866308757. The next prime is 20811866308801. The reversal of 20811866308790 is 9780366811802.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 68249681 + ... + 68553939.

It is an arithmetic number, because the mean of its divisors is an integer number (607451438880).

Almost surely, 2^{20811866308790} is an apocalyptic number.

20811866308790 is a deficient number, since it is larger than the sum of its proper divisors (18065025779530).

20811866308790 is a wasteful number, since it uses less digits than its factorization.

20811866308790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305477.

The product of its (nonzero) digits is 6967296, while the sum is 59.

The spelling of 20811866308790 in words is "twenty trillion, eight hundred eleven billion, eight hundred sixty-six million, three hundred eight thousand, seven hundred ninety".