2131321 has 2 divisors, whose sum is σ = 2131322. Its totient is φ = 2131320.

The previous prime is 2131319. The next prime is 2131361. The reversal of 2131321 is 1231312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2016400 + 114921 = 1420^2 + 339^2 .

It is a cyclic number.

It is not a de Polignac number, because 2131321 - 2¹ = 2131319 is a prime.

Together with 2131319, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

2131321 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (2131361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1065660 + 1065661.

It is an arithmetic number, because the mean of its divisors is an integer number (1065661).

2^2131321 is an apocalyptic number.

It is an amenable number.

2131321 is a deficient number, since it is larger than the sum of its proper divisors (1).

2131321 is an equidigital number, since it uses as much as digits as its factorization.

2131321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36, while the sum is 13.

The square root of 2131321 is about 1459.9044489281. The cubic root of 2131321 is about 128.6914284122.

Adding to 2131321 its reverse (1231312), we get a palindrome (3362633).

Subtracting from 2131321 its reverse (1231312), we obtain a palindrome (900009).

The spelling of 2131321 in words is "two million, one hundred thirty-one thousand, three hundred twenty-one".