20112121 has 4 divisors (see below), whose sum is σ = 20121700. Its totient is φ = 20102544.

The previous prime is 20112119. The next prime is 20112133. The reversal of 20112121 is 12121102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 2134521 + 17977600 = 1461^2 + 4240^2 .

It is a cyclic number.

It is not a de Polignac number, because 20112121 - 2¹ = 20112119 is a prime.

It is a super-2 number, since 2×20112121² = 808994822237282, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20112098 and 20112107.

It is not an unprimeable number, because it can be changed into a prime (20112151) 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, 126 + ... + 6343.

It is an arithmetic number, because the mean of its divisors is an integer number (5030425).

Almost surely, 2^20112121 is an apocalyptic number.

It is an amenable number.

20112121 is a deficient number, since it is larger than the sum of its proper divisors (9579).

20112121 is an equidigital number, since it uses as much as digits as its factorization.

20112121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9578.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 20112121 is about 4484.6539442860. The cubic root of 20112121 is about 271.9480554281.

Adding to 20112121 its reverse (12121102), we get a palindrome (32233223).

The spelling of 20112121 in words is "twenty million, one hundred twelve thousand, one hundred twenty-one".