664945584 has 80 divisors (see below), whose sum is σ = 1822740480. Its totient is φ = 208293120.

The previous prime is 664945583. The next prime is 664945591. The reversal of 664945584 is 485549466.

It is a super-2 number, since 2×664945584² = 884305259362202112, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (664945583) 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 15 ways as a sum of consecutive naturals, for example, 112954 + ... + 118694.

It is an arithmetic number, because the mean of its divisors is an integer number (22784256).

Almost surely, 2^664945584 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 664945584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (911370240).

664945584 is an abundant number, since it is smaller than the sum of its proper divisors (1157794896).

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

664945584 is a wasteful number, since it uses less digits than its factorization.

664945584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5898 (or 5892 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 51.

The square root of 664945584 is about 25786.5388138850. The cubic root of 664945584 is about 872.8280647952.

The spelling of 664945584 in words is "six hundred sixty-four million, nine hundred forty-five thousand, five hundred eighty-four".