23431721 has 2 divisors, whose sum is σ = 23431722. Its totient is φ = 23431720.

The previous prime is 23431711. The next prime is 23431757. The reversal of 23431721 is 12713432.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17106496 + 6325225 = 4136^2 + 2515^2 .

It is a cyclic number.

It is not a de Polignac number, because 23431721 - 2⁶ = 23431657 is a prime.

It is not a weakly prime, because it can be changed into another prime (23431711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11715860 + 11715861.

It is an arithmetic number, because the mean of its divisors is an integer number (11715861).

Almost surely, 2^23431721 is an apocalyptic number.

It is an amenable number.

23431721 is a deficient number, since it is larger than the sum of its proper divisors (1).

23431721 is an equidigital number, since it uses as much as digits as its factorization.

23431721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008, while the sum is 23.

The square root of 23431721 is about 4840.6322934096. The cubic root of 23431721 is about 286.1550376254.

The spelling of 23431721 in words is "twenty-three million, four hundred thirty-one thousand, seven hundred twenty-one".