666998889959 has 2 divisors, whose sum is σ = 666998889960. Its totient is φ = 666998889958.

The previous prime is 666998889871. The next prime is 666998890007. The reversal of 666998889959 is 959988899666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 666998889959 - 2¹⁶ = 666998824423 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666998889659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333499444979 + 333499444980.

It is an arithmetic number, because the mean of its divisors is an integer number (333499444980).

Almost surely, 2^666998889959 is an apocalyptic number.

666998889959 is a deficient number, since it is larger than the sum of its proper divisors (1).

666998889959 is an equidigital number, since it uses as much as digits as its factorization.

666998889959 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32651735040, while the sum is 92.

The spelling of 666998889959 in words is "six hundred sixty-six billion, nine hundred ninety-eight million, eight hundred eighty-nine thousand, nine hundred fifty-nine".