664992720 has 480 divisors, whose sum is σ = 2734467840. Its totient is φ = 148055040.

The previous prime is 664992709. The next prime is 664992737. The reversal of 664992720 is 27299466.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6456189 + ... + 6456291.

It is an arithmetic number, because the mean of its divisors is an integer number (5696808).

Almost surely, 2^664992720 is an apocalyptic number.

664992720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664992720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1367233920).

664992720 is an abundant number, since it is smaller than the sum of its proper divisors (2069475120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664992720 is a wasteful number, since it uses less digits than its factorization.

664992720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200 (or 181 counting only the distinct ones).

The product of its (nonzero) digits is 326592, while the sum is 45.

The square root of 664992720 is about 25787.4527629233. The cubic root of 664992720 is about 872.8486883633.

The spelling of 664992720 in words is "six hundred sixty-four million, nine hundred ninety-two thousand, seven hundred twenty".