21112221111121 has 8 divisors (see below), whose sum is σ = 24620666019200. Its totient is φ = 18096189523524.

The previous prime is 21112221111101. The next prime is 21112221111221. The reversal of 21112221111121 is 12111112221112.

It is not a de Polignac number, because 21112221111121 - 2¹⁹ = 21112220586833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112221111101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30775832181 + ... + 30775832866.

It is an arithmetic number, because the mean of its divisors is an integer number (3077583252400).

Almost surely, 2^{21112221111121} is an apocalyptic number.

It is an amenable number.

21112221111121 is a deficient number, since it is larger than the sum of its proper divisors (3508444908079).

21112221111121 is an frugal number, since it uses more digits than its factorization.

21112221111121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61551665068 (or 61551665054 counting only the distinct ones).

The product of its digits is 32, while the sum is 19.

Adding to 21112221111121 its reverse (12111112221112), we get a palindrome (33223333332233).

The spelling of 21112221111121 in words is "twenty-one trillion, one hundred twelve billion, two hundred twenty-one million, one hundred eleven thousand, one hundred twenty-one".