664186572 has 216 divisors, whose sum is σ = 2080260000. Its totient is φ = 178573248.

The previous prime is 664186561. The next prime is 664186577. The reversal of 664186572 is 275681466.

664186572 is a `hidden beast` number, since 6 + 64 + 18 + 6 + 572 = 666.

It is a super-2 number, since 2×664186572² = 882287604850222368, which contains 22 as substring.

Its product of digits (483840) is a multiple of the sum of its prime divisors (180).

It is not an unprimeable number, because it can be changed into a prime (664186577) by changing a digit.

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 71 ways as a sum of consecutive naturals, for example, 4457554 + ... + 4457702.

Almost surely, 2^664186572 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 664186572, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1040130000).

664186572 is an abundant number, since it is smaller than the sum of its proper divisors (1416073428).

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

664186572 is a wasteful number, since it uses less digits than its factorization.

664186572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 180 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 664186572 is about 25771.8173980804. The cubic root of 664186572 is about 872.4958375075.

The spelling of 664186572 in words is "six hundred sixty-four million, one hundred eighty-six thousand, five hundred seventy-two".