2131123221 has 12 divisors (see below), whose sum is σ = 3080470848. Its totient is φ = 1419741864.

The previous prime is 2131123207. The next prime is 2131123223. The reversal of 2131123221 is 1223211312.

It is not a de Polignac number, because 2131123221 - 2⁶ = 2131123157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2131123194 and 2131123203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2131123223) 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, 70395 + ... + 96008.

It is an arithmetic number, because the mean of its divisors is an integer number (256705904).

Almost surely, 2^2131123221 is an apocalyptic number.

It is an amenable number.

2131123221 is a deficient number, since it is larger than the sum of its proper divisors (949347627).

2131123221 is a wasteful number, since it uses less digits than its factorization.

2131123221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167832 (or 167829 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 2131123221 is about 46164.0901675751. The cubic root of 2131123221 is about 1286.8744758700.

Adding to 2131123221 its reverse (1223211312), we get a palindrome (3354334533).

The spelling of 2131123221 in words is "two billion, one hundred thirty-one million, one hundred twenty-three thousand, two hundred twenty-one".