20212222121 has 24 divisors (see below), whose sum is σ = 25335079560. Its totient is φ = 15983073792.

The previous prime is 20212222087. The next prime is 20212222123. The reversal of 20212222121 is 12122221202.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1388382121 + 18823840000 = 37261^2 + 137200^2 .

It is not a de Polignac number, because 20212222121 - 2¹⁴ = 20212205737 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20212222121.

It is not an unprimeable number, because it can be changed into a prime (20212222123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1264145 + ... + 1280033.

It is an arithmetic number, because the mean of its divisors is an integer number (1055628315).

Almost surely, 2^20212222121 is an apocalyptic number.

It is an amenable number.

20212222121 is a deficient number, since it is larger than the sum of its proper divisors (5122857439).

20212222121 is a wasteful number, since it uses less digits than its factorization.

20212222121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17913 (or 17906 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 20212222121 its reverse (12122221202), we get a palindrome (32334443323).

The spelling of 20212222121 in words is "twenty billion, two hundred twelve million, two hundred twenty-two thousand, one hundred twenty-one".