664680 has 64 divisors (see below), whose sum is σ = 2073600. Its totient is φ = 170240.

The previous prime is 664679. The next prime is 664687. The reversal of 664680 is 86466.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (664687) 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 15 ways as a sum of consecutive naturals, for example, 3385 + ... + 3575.

It is an arithmetic number, because the mean of its divisors is an integer number (32400).

2⁶⁶⁴⁶⁸⁰ is an apocalyptic number.

664680 is a gapful number since it is divisible by the number (60) 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 664680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1036800).

664680 is an abundant number, since it is smaller than the sum of its proper divisors (1408920).

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

664680 is a wasteful number, since it uses less digits than its factorization.

664680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 664680 is about 815.2790933171. The cubic root of 664680 is about 87.2711844740.

The spelling of 664680 in words is "six hundred sixty-four thousand, six hundred eighty".