2131320121 has 6 divisors (see below), whose sum is σ = 2479290810. Its totient is φ = 1826845776.

The previous prime is 2131320119. The next prime is 2131320127. The reversal of 2131320121 is 1210231312.

It can be written as a sum of positive squares in only one way, i.e., 2131207225 + 112896 = 46165^2 + 336^2 .

It is not a de Polignac number, because 2131320121 - 2¹ = 2131320119 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2131320095 and 2131320104.

It is not an unprimeable number, because it can be changed into a prime (2131320127) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21748116 + ... + 21748213.

It is an arithmetic number, because the mean of its divisors is an integer number (413215135).

Almost surely, 2^2131320121 is an apocalyptic number.

It is an amenable number.

2131320121 is a deficient number, since it is larger than the sum of its proper divisors (347970689).

2131320121 is an equidigital number, since it uses as much as digits as its factorization.

2131320121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43496343 (or 43496336 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 2131320121 is about 46166.2227283108. Note that the first 3 decimals coincide. The cubic root of 2131320121 is about 1286.9141072059.

Adding to 2131320121 its reverse (1210231312), we get a palindrome (3341551433).

The spelling of 2131320121 in words is "two billion, one hundred thirty-one million, three hundred twenty thousand, one hundred twenty-one".