664811699 has 2 divisors, whose sum is σ = 664811700. Its totient is φ = 664811698.

The previous prime is 664811683. The next prime is 664811717. The reversal of 664811699 is 996118466.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 664811699 - 2⁴ = 664811683 is a prime.

It is not a weakly prime, because it can be changed into another prime (664811659) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332405849 + 332405850.

It is an arithmetic number, because the mean of its divisors is an integer number (332405850).

Almost surely, 2^664811699 is an apocalyptic number.

664811699 is a deficient number, since it is larger than the sum of its proper divisors (1).

664811699 is an equidigital number, since it uses as much as digits as its factorization.

664811699 is an evil number, because the sum of its binary digits is even.

The product of its digits is 559872, while the sum is 50.

The square root of 664811699 is about 25783.9426581739. The cubic root of 664811699 is about 872.7694803375.

The spelling of 664811699 in words is "six hundred sixty-four million, eight hundred eleven thousand, six hundred ninety-nine".