664523808 has 96 divisors (see below), whose sum is σ = 1883782656. Its totient is φ = 203900928.

The previous prime is 664523773. The next prime is 664523851. The reversal of 664523808 is 808325466.

It is a tau number, because it is divible by the number of its divisors (96).

It is a self number, because there is not a number n which added to its sum of digits gives 664523808.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 769585 + ... + 770447.

It is an arithmetic number, because the mean of its divisors is an integer number (19622736).

Almost surely, 2^664523808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 664523808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (941891328).

664523808 is an abundant number, since it is smaller than the sum of its proper divisors (1219258848).

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

664523808 is a wasteful number, since it uses less digits than its factorization.

664523808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1506 (or 1498 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 42.

The square root of 664523808 is about 25778.3592961228. The cubic root of 664523808 is about 872.6434803706.

The spelling of 664523808 in words is "six hundred sixty-four million, five hundred twenty-three thousand, eight hundred eight".