664576 has 44 divisors (see below), whose sum is σ = 1473840. Its totient is φ = 296960.

The previous prime is 664571. The next prime is 664579. The reversal of 664576 is 675466.

It is a tau number, because it is divible by the number of its divisors (44).

It is a super-2 number, since 2×664576² = 883322519552, which contains 22 as substring.

It is an Ulam number.

Its product of digits (30240) is a multiple of the sum of its prime divisors (72).

It is a plaindrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (664571) by changing a digit.

664576 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11235 + ... + 11293.

2⁶⁶⁴⁵⁷⁶ 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 664576, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (736920).

664576 is an abundant number, since it is smaller than the sum of its proper divisors (809264).

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

664576 is a wasteful number, since it uses less digits than its factorization.

664576 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90 (or 72 counting only the distinct ones).

The product of its digits is 30240, while the sum is 34.

The square root of 664576 is about 815.2153089828. The cubic root of 664576 is about 87.2666325710.

The spelling of 664576 in words is "six hundred sixty-four thousand, five hundred seventy-six".