666304 has 28 divisors (see below), whose sum is σ = 1371600. Its totient is φ = 320768.

The previous prime is 666301. The next prime is 666329. The reversal of 666304 is 403666.

It is a happy number.

It is a super-2 number, since 2×666304² = 887922040832, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (666301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1677 + ... + 2035.

2⁶⁶⁶³⁰⁴ is an apocalyptic number.

666304 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (685800).

666304 is an abundant number, since it is smaller than the sum of its proper divisors (705296).

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

666304 is a wasteful number, since it uses less digits than its factorization.

666304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400 (or 390 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 666304 is about 816.2744636457. The cubic root of 666304 is about 87.3422026745.

The spelling of 666304 in words is "six hundred sixty-six thousand, three hundred four".