23236721 has 2 divisors, whose sum is σ = 23236722. Its totient is φ = 23236720.

The previous prime is 23236687. The next prime is 23236723. The reversal of 23236721 is 12763232.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 22657600 + 579121 = 4760^2 + 761^2 .

It is a cyclic number.

It is not a de Polignac number, because 23236721 - 2⁶ = 23236657 is a prime.

Together with 23236723, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (23236723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11618360 + 11618361.

It is an arithmetic number, because the mean of its divisors is an integer number (11618361).

Almost surely, 2^23236721 is an apocalyptic number.

It is an amenable number.

23236721 is a deficient number, since it is larger than the sum of its proper divisors (1).

23236721 is an equidigital number, since it uses as much as digits as its factorization.

23236721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 26.

The square root of 23236721 is about 4820.4482156746. The cubic root of 23236721 is about 285.3590263437.

Adding to 23236721 its reverse (12763232), we get a palindrome (35999953).

The spelling of 23236721 in words is "twenty-three million, two hundred thirty-six thousand, seven hundred twenty-one".