23555566399 has 2 divisors, whose sum is σ = 23555566400. Its totient is φ = 23555566398.

The previous prime is 23555566393. The next prime is 23555566423. The reversal of 23555566399 is 99366555532.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 23555566399 - 2²⁵ = 23522011967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23555566393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11777783199 + 11777783200.

It is an arithmetic number, because the mean of its divisors is an integer number (11777783200).

Almost surely, 2^23555566399 is an apocalyptic number.

23555566399 is a deficient number, since it is larger than the sum of its proper divisors (1).

23555566399 is an equidigital number, since it uses as much as digits as its factorization.

23555566399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32805000, while the sum is 58.

The spelling of 23555566399 in words is "twenty-three billion, five hundred fifty-five million, five hundred sixty-six thousand, three hundred ninety-nine".