23664821 has 2 divisors, whose sum is σ = 23664822. Its totient is φ = 23664820.

The previous prime is 23664787. The next prime is 23664827. The reversal of 23664821 is 12846632.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19704721 + 3960100 = 4439^2 + 1990^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23664821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23664827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11832410 + 11832411.

It is an arithmetic number, because the mean of its divisors is an integer number (11832411).

Almost surely, 2^23664821 is an apocalyptic number.

It is an amenable number.

23664821 is a deficient number, since it is larger than the sum of its proper divisors (1).

23664821 is an equidigital number, since it uses as much as digits as its factorization.

23664821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13824, while the sum is 32.

The square root of 23664821 is about 4864.6501415826. The cubic root of 23664821 is about 287.1008034983.

The spelling of 23664821 in words is "twenty-three million, six hundred sixty-four thousand, eight hundred twenty-one".