23985991 has 2 divisors, whose sum is σ = 23985992. Its totient is φ = 23985990.

The previous prime is 23985977. The next prime is 23986003. The reversal of 23985991 is 19958932.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 23985991 - 2²³ = 15597383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23985191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11992995 + 11992996.

It is an arithmetic number, because the mean of its divisors is an integer number (11992996).

Almost surely, 2^23985991 is an apocalyptic number.

23985991 is a deficient number, since it is larger than the sum of its proper divisors (1).

23985991 is an equidigital number, since it uses as much as digits as its factorization.

23985991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 174960, while the sum is 46.

The square root of 23985991 is about 4897.5494892854. The cubic root of 23985991 is about 288.3937795985.

It can be divided in two parts, 23985 and 991, that added together give a triangular number (24976 = T₂₂₃).

The spelling of 23985991 in words is "twenty-three million, nine hundred eighty-five thousand, nine hundred ninety-one".