It is a tau number, because it is divible by the number of its divisors (80).
It is a congruent number.
646000 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
2646000 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 646000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (870480).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
646000 is a wasteful number, since it uses less digits than its factorization.
646000 is an odious number, because the sum of its binary digits is odd.
The square root of 646000 is about 803.7412518964. The cubic root of 646000 is about 86.4458547175.
Adding to 646000 its reverse (646), we get a palindrome (646646).
646000 divided by its reverse (646) gives a cube (1000 = 103).
The spelling of 646000 in words is "six hundred forty-six thousand".