664360520 has 48 divisors (see below), whose sum is σ = 1562678460. Its totient is φ = 254182016.

The previous prime is 664360513. The next prime is 664360537. The reversal of 664360520 is 25063466.

It can be written as a sum of positive squares in 2 ways, for example, as 656486884 + 7873636 = 25622^2 + 2806^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5462 + ... + 36858.

Almost surely, 2^664360520 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 664360520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (781339230).

664360520 is an abundant number, since it is smaller than the sum of its proper divisors (898317940).

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

664360520 is a wasteful number, since it uses less digits than its factorization.

664360520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31454 (or 31427 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 32.

The square root of 664360520 is about 25775.1919488488. The cubic root of 664360520 is about 872.5719986671.

The spelling of 664360520 in words is "six hundred sixty-four million, three hundred sixty thousand, five hundred twenty".