23116721 has 2 divisors, whose sum is σ = 23116722. Its totient is φ = 23116720.

The previous prime is 23116693. The next prime is 23116739. The reversal of 23116721 is 12761132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20430400 + 2686321 = 4520^2 + 1639^2 .

It is a cyclic number.

It is not a de Polignac number, because 23116721 - 2⁶ = 23116657 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (23116781) 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 as a sum of consecutive naturals, namely, 11558360 + 11558361.

It is an arithmetic number, because the mean of its divisors is an integer number (11558361).

Almost surely, 2^23116721 is an apocalyptic number.

It is an amenable number.

23116721 is a deficient number, since it is larger than the sum of its proper divisors (1).

23116721 is an equidigital number, since it uses as much as digits as its factorization.

23116721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 504, while the sum is 23.

The square root of 23116721 is about 4807.9851289287. The cubic root of 23116721 is about 284.8669574991.

Adding to 23116721 its reverse (12761132), we get a palindrome (35877853).

The spelling of 23116721 in words is "twenty-three million, one hundred sixteen thousand, seven hundred twenty-one".