664560 has 120 divisors (see below), whose sum is σ = 2437344. Its totient is φ = 161280.

The previous prime is 664549. The next prime is 664561. The reversal of 664560 is 65466.

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664561) by changing a digit.

664560 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 23 ways as a sum of consecutive naturals, for example, 9325 + ... + 9395.

2⁶⁶⁴⁵⁶⁰ is an apocalyptic number.

664560 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 664560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1218672).

664560 is an abundant number, since it is smaller than the sum of its proper divisors (1772784).

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

664560 is a wasteful number, since it uses less digits than its factorization.

664560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 664560 is about 815.2054955654. The cubic root of 664560 is about 87.2659322361.

The spelling of 664560 in words is "six hundred sixty-four thousand, five hundred sixty".