23638921 has 2 divisors, whose sum is σ = 23638922. Its totient is φ = 23638920.

The previous prime is 23638883. The next prime is 23638931. The reversal of 23638921 is 12983632.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23619600 + 19321 = 4860^2 + 139^2 .

It is a cyclic number.

It is not a de Polignac number, because 23638921 - 2¹⁵ = 23606153 is a 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 (23638931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11819460 + 11819461.

It is an arithmetic number, because the mean of its divisors is an integer number (11819461).

Almost surely, 2^23638921 is an apocalyptic number.

It is an amenable number.

23638921 is a deficient number, since it is larger than the sum of its proper divisors (1).

23638921 is an equidigital number, since it uses as much as digits as its factorization.

23638921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15552, while the sum is 34.

The square root of 23638921 is about 4861.9873508680. The cubic root of 23638921 is about 286.9960259580.

The spelling of 23638921 in words is "twenty-three million, six hundred thirty-eight thousand, nine hundred twenty-one".