664708985 has 16 divisors (see below), whose sum is σ = 802992960. Its totient is φ = 528219840.

The previous prime is 664708973. The next prime is 664708997. The reversal of 664708985 is 589807466.

It is an interprime number because it is at equal distance from previous prime (664708973) and next prime (664708997).

It is not a de Polignac number, because 664708985 - 2⁴ = 664708969 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 651806 + ... + 652824.

It is an arithmetic number, because the mean of its divisors is an integer number (50187060).

Almost surely, 2^664708985 is an apocalyptic number.

It is an amenable number.

664708985 is a deficient number, since it is larger than the sum of its proper divisors (138283975).

664708985 is a wasteful number, since it uses less digits than its factorization.

664708985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1768.

The product of its (nonzero) digits is 2903040, while the sum is 53.

The square root of 664708985 is about 25781.9507601733. The cubic root of 664708985 is about 872.7245301349.

The spelling of 664708985 in words is "six hundred sixty-four million, seven hundred eight thousand, nine hundred eighty-five".