663666659 has 2 divisors, whose sum is σ = 663666660. Its totient is φ = 663666658.

The previous prime is 663666571. The next prime is 663666677. The reversal of 663666659 is 956666366.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 663666659 - 2¹² = 663662563 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 663666659.

It is not a weakly prime, because it can be changed into another prime (663666359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331833329 + 331833330.

It is an arithmetic number, because the mean of its divisors is an integer number (331833330).

Almost surely, 2^663666659 is an apocalyptic number.

663666659 is a deficient number, since it is larger than the sum of its proper divisors (1).

663666659 is an equidigital number, since it uses as much as digits as its factorization.

663666659 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6298560, while the sum is 53.

The square root of 663666659 is about 25761.7285716623. The cubic root of 663666659 is about 872.2681201957.

The spelling of 663666659 in words is "six hundred sixty-three million, six hundred sixty-six thousand, six hundred fifty-nine".