23991559 has 2 divisors, whose sum is σ = 23991560. Its totient is φ = 23991558.

The previous prime is 23991557. The next prime is 23991571. The reversal of 23991559 is 95519932.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 23991559 - 2¹ = 23991557 is a prime.

Together with 23991557, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23991557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11995779 + 11995780.

It is an arithmetic number, because the mean of its divisors is an integer number (11995780).

Almost surely, 2^23991559 is an apocalyptic number.

23991559 is a deficient number, since it is larger than the sum of its proper divisors (1).

23991559 is an equidigital number, since it uses as much as digits as its factorization.

23991559 is an evil number, because the sum of its binary digits is even.

The product of its digits is 109350, while the sum is 43.

The square root of 23991559 is about 4898.1179038484. The cubic root of 23991559 is about 288.4160933500.

The spelling of 23991559 in words is "twenty-three million, nine hundred ninety-one thousand, five hundred fifty-nine".