20011111111091 has 16 divisors (see below), whose sum is σ = 20689613672448. Its totient is φ = 19334673885600.

The previous prime is 20011111111039. The next prime is 20011111111213. The reversal of 20011111111091 is 19011111111002.

It is a happy number.

It is not a de Polignac number, because 20011111111091 - 2²⁶ = 20011044002227 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20011111117091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 508302290 + ... + 508341656.

It is an arithmetic number, because the mean of its divisors is an integer number (1293100854528).

Almost surely, 2^{20011111111091} is an apocalyptic number.

20011111111091 is a deficient number, since it is larger than the sum of its proper divisors (678502561357).

20011111111091 is a wasteful number, since it uses less digits than its factorization.

20011111111091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65162.

The product of its (nonzero) digits is 18, while the sum is 20.

Adding to 20011111111091 its reverse (19011111111002), we get a palindrome (39022222222093).

The spelling of 20011111111091 in words is "twenty trillion, eleven billion, one hundred eleven million, one hundred eleven thousand, ninety-one".