66231554399 has 2 divisors, whose sum is σ = 66231554400. Its totient is φ = 66231554398.

The previous prime is 66231554393. The next prime is 66231554437. The reversal of 66231554399 is 99345513266.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66231554399 - 2¹⁶ = 66231488863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66231554399.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66231554393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33115777199 + 33115777200.

It is an arithmetic number, because the mean of its divisors is an integer number (33115777200).

Almost surely, 2^66231554399 is an apocalyptic number.

66231554399 is a deficient number, since it is larger than the sum of its proper divisors (1).

66231554399 is an equidigital number, since it uses as much as digits as its factorization.

66231554399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5248800, while the sum is 53.

The spelling of 66231554399 in words is "sixty-six billion, two hundred thirty-one million, five hundred fifty-four thousand, three hundred ninety-nine".