646500 has 48 divisors (see below), whose sum is σ = 1886976. Its totient is φ = 172000.

The previous prime is 646453. The next prime is 646519. The reversal of 646500 is 5646.

It is a nialpdrome in base 15.

It is an unprimeable number.

646500 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1285 + ... + 1715.

It is an arithmetic number, because the mean of its divisors is an integer number (39312).

2⁶⁴⁶⁵⁰⁰ is an apocalyptic number.

646500 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 646500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (943488).

646500 is an abundant number, since it is smaller than the sum of its proper divisors (1240476).

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

646500 is a wasteful number, since it uses less digits than its factorization.

646500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453 (or 441 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 646500 is about 804.0522371090. The cubic root of 646500 is about 86.4681518180.

The spelling of 646500 in words is "six hundred forty-six thousand, five hundred".