23966921921 has 2 divisors, whose sum is σ = 23966921922. Its totient is φ = 23966921920.

The previous prime is 23966921857. The next prime is 23966921941. The reversal of 23966921921 is 12912966932.

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., 19321000000 + 4645921921 = 139000^2 + 68161^2 .

It is a cyclic number.

It is not a de Polignac number, because 23966921921 - 2⁶ = 23966921857 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 23966921921.

It is not a weakly prime, because it can be changed into another prime (23966921941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11983460960 + 11983460961.

It is an arithmetic number, because the mean of its divisors is an integer number (11983460961).

Almost surely, 2^23966921921 is an apocalyptic number.

It is an amenable number.

23966921921 is a deficient number, since it is larger than the sum of its proper divisors (1).

23966921921 is an equidigital number, since it uses as much as digits as its factorization.

23966921921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 629856, while the sum is 50.

The spelling of 23966921921 in words is "twenty-three billion, nine hundred sixty-six million, nine hundred twenty-one thousand, nine hundred twenty-one".