664520832 has 96 divisors (see below), whose sum is σ = 1918363980. Its totient is φ = 220796928.

The previous prime is 664520797. The next prime is 664520833. The reversal of 664520832 is 238025466.

664520832 is a `hidden beast` number, since 6 + 645 + 2 + 0 + 8 + 3 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 563397696 + 101123136 = 23736^2 + 10056^2 .

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

It is a super-3 number, since 3×664520832³ (a number of 27 digits) contains 333 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (664520833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 456618 + ... + 458070.

Almost surely, 2^664520832 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 664520832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (959181990).

664520832 is an abundant number, since it is smaller than the sum of its proper divisors (1253843148).

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

664520832 is a wasteful number, since it uses less digits than its factorization.

664520832 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1870 (or 1855 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 664520832 is about 25778.3015732224. The cubic root of 664520832 is about 872.6421776879.

The spelling of 664520832 in words is "six hundred sixty-four million, five hundred twenty thousand, eight hundred thirty-two".