21102020122111 has 4 divisors (see below), whose sum is σ = 21218605868824. Its totient is φ = 20985434375400.

The previous prime is 21102020122081. The next prime is 21102020122159. The reversal of 21102020122111 is 11122102020112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21102020122111 - 2²¹ = 21102018024959 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 (21102020123111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58292873085 + ... + 58292873446.

It is an arithmetic number, because the mean of its divisors is an integer number (5304651467206).

Almost surely, 2^{21102020122111} is an apocalyptic number.

21102020122111 is a deficient number, since it is larger than the sum of its proper divisors (116585746713).

21102020122111 is a wasteful number, since it uses less digits than its factorization.

21102020122111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116585746712.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21102020122111 its reverse (11122102020112), we get a palindrome (32224122142223).

The spelling of 21102020122111 in words is "twenty-one trillion, one hundred two billion, twenty million, one hundred twenty-two thousand, one hundred eleven".