664000 has 56 divisors (see below), whose sum is σ = 1664208. Its totient is φ = 262400.

The previous prime is 663997. The next prime is 664009. The reversal of 664000 is 466.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7959 + ... + 8041.

It is an arithmetic number, because the mean of its divisors is an integer number (29718).

2⁶⁶⁴⁰⁰⁰ 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 664000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (832104).

664000 is an abundant number, since it is smaller than the sum of its proper divisors (1000208).

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

664000 is an equidigital number, since it uses as much as digits as its factorization.

664000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 664000 is about 814.8619514985. The cubic root of 664000 is about 87.2414134291.

Adding to 664000 its reverse (466), we get a palindrome (664466).

The spelling of 664000 in words is "six hundred sixty-four thousand".