664239999 has 8 divisors (see below), whose sum is σ = 886490752. Its totient is φ = 442407960.

The previous prime is 664239991. The next prime is 664240009. The reversal of 664239999 is 999932466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 664239999 - 2³ = 664239991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664239991) 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 in 7 ways as a sum of consecutive naturals, for example, 100957 + ... + 107334.

It is an arithmetic number, because the mean of its divisors is an integer number (110811344).

Almost surely, 2^664239999 is an apocalyptic number.

664239999 is a deficient number, since it is larger than the sum of its proper divisors (222250753).

664239999 is a wasteful number, since it uses less digits than its factorization.

664239999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209357.

The product of its digits is 5668704, while the sum is 57.

The square root of 664239999 is about 25772.8539164758. The cubic root of 664239999 is about 872.5192313284.

The spelling of 664239999 in words is "six hundred sixty-four million, two hundred thirty-nine thousand, nine hundred ninety-nine".