20212122121 has 12 divisors (see below), whose sum is σ = 20625816780. Its totient is φ = 19804761600.

The previous prime is 20212122107. The next prime is 20212122143. The reversal of 20212122121 is 12122121202.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 1594884096 + 18617238025 = 39936^2 + 136445^2 .

It is not a de Polignac number, because 20212122121 - 2¹⁷ = 20211991049 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20212122095 and 20212122104.

It is not an unprimeable number, because it can be changed into a prime (20212122101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 939675 + ... + 960943.

It is an arithmetic number, because the mean of its divisors is an integer number (1718818065).

Almost surely, 2^20212122121 is an apocalyptic number.

It is an amenable number.

20212122121 is a deficient number, since it is larger than the sum of its proper divisors (413694659).

20212122121 is an equidigital number, since it uses as much as digits as its factorization.

20212122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21564 (or 21467 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20212122121 its reverse (12122121202), we get a palindrome (32334243323).

It can be divided in two parts, 202 and 12122121, that multiplied together give a palindrome (2448668442).

The spelling of 20212122121 in words is "twenty billion, two hundred twelve million, one hundred twenty-two thousand, one hundred twenty-one".