23131321 has 4 divisors (see below), whose sum is σ = 23140944. Its totient is φ = 23121700.

The previous prime is 23131289. The next prime is 23131333. The reversal of 23131321 is 12313132.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 23131321 - 2⁵ = 23131289 is a prime.

It is a super-2 number, since 2×23131321² = 1070116022410082, 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 = 23131295 and 23131304.

It is not an unprimeable number, because it can be changed into a prime (23131351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2226 + ... + 7156.

It is an arithmetic number, because the mean of its divisors is an integer number (5785236).

Almost surely, 2^23131321 is an apocalyptic number.

It is an amenable number.

23131321 is a deficient number, since it is larger than the sum of its proper divisors (9623).

23131321 is an equidigital number, since it uses as much as digits as its factorization.

23131321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9622.

The product of its digits is 108, while the sum is 16.

The square root of 23131321 is about 4809.5031967969. The cubic root of 23131321 is about 284.9269167280.

Adding to 23131321 its reverse (12313132), we get a palindrome (35444453).

The spelling of 23131321 in words is "twenty-three million, one hundred thirty-one thousand, three hundred twenty-one".