211102111220021 has 6 divisors (see below), whose sum is σ = 245567762031510. Its totient is φ = 180944666759976.

The previous prime is 211102111220017. The next prime is 211102111220069. The reversal of 211102111220021 is 120022111201112.

It can be written as a sum of positive squares in only one way, i.e., 189854943633796 + 21247167586225 = 13778786^2 + 4609465^2 .

It is not a de Polignac number, because 211102111220021 - 2² = 211102111220017 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 (211102111220621) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2154103175666 + ... + 2154103175763.

It is an arithmetic number, because the mean of its divisors is an integer number (40927960338585).

Almost surely, 2^{211102111220021} is an apocalyptic number.

It is an amenable number.

211102111220021 is a deficient number, since it is larger than the sum of its proper divisors (34465650811489).

211102111220021 is an equidigital number, since it uses as much as digits as its factorization.

211102111220021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4308206351443 (or 4308206351436 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 211102111220021 its reverse (120022111201112), we get a palindrome (331124222421133).

The spelling of 211102111220021 in words is "two hundred eleven trillion, one hundred two billion, one hundred eleven million, two hundred twenty thousand, twenty-one".