664902720 has 336 divisors, whose sum is σ = 2496312000. Its totient is φ = 161796096.

The previous prime is 664902703. The next prime is 664902727. The reversal of 664902720 is 27209466.

It is a happy number.

664902720 is a `hidden beast` number, since 6 + 649 + 0 + 2 + 7 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664902727) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1586671 + ... + 1587089.

It is an arithmetic number, because the mean of its divisors is an integer number (7429500).

Almost surely, 2^664902720 is an apocalyptic number.

664902720 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 664902720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1248156000).

664902720 is an abundant number, since it is smaller than the sum of its proper divisors (1831409280).

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

664902720 is a wasteful number, since it uses less digits than its factorization.

664902720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490 (or 477 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 36.

The square root of 664902720 is about 25785.7076691721. The cubic root of 664902720 is about 872.8093095231.

The spelling of 664902720 in words is "six hundred sixty-four million, nine hundred two thousand, seven hundred twenty".