20131321 has 4 divisors (see below), whose sum is σ = 23007232. Its totient is φ = 17255412.

The previous prime is 20131313. The next prime is 20131339. The reversal of 20131321 is 12313102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20131321 - 2³ = 20131313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20131381) 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, 1437945 + ... + 1437958.

It is an arithmetic number, because the mean of its divisors is an integer number (5751808).

Almost surely, 2^20131321 is an apocalyptic number.

It is an amenable number.

20131321 is a deficient number, since it is larger than the sum of its proper divisors (2875911).

20131321 is an equidigital number, since it uses as much as digits as its factorization.

20131321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2875910.

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

The square root of 20131321 is about 4486.7940670372. The cubic root of 20131321 is about 272.0345661449.

Adding to 20131321 its reverse (12313102), we get a palindrome (32444423).

The spelling of 20131321 in words is "twenty million, one hundred thirty-one thousand, three hundred twenty-one".