23815991 has 2 divisors, whose sum is σ = 23815992. Its totient is φ = 23815990.

The previous prime is 23815973. The next prime is 23816003. The reversal of 23815991 is 19951832.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23815991 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23815951) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11907995 + 11907996.

It is an arithmetic number, because the mean of its divisors is an integer number (11907996).

Almost surely, 2^23815991 is an apocalyptic number.

23815991 is a deficient number, since it is larger than the sum of its proper divisors (1).

23815991 is an equidigital number, since it uses as much as digits as its factorization.

23815991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19440, while the sum is 38.

The square root of 23815991 is about 4880.1630095725. The cubic root of 23815991 is about 287.7108361472.

The spelling of 23815991 in words is "twenty-three million, eight hundred fifteen thousand, nine hundred ninety-one".