646884 has 72 divisors (see below), whose sum is σ = 1991808. Its totient is φ = 172800.

The previous prime is 646883. The next prime is 646889. The reversal of 646884 is 488646.

646884 = T₁₂₇ + T₁₂₈ + ... + T₁₈₀.

646884 is a `hidden beast` number, since 646 + 8 + 8 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (646883) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4209 + ... + 4359.

It is an arithmetic number, because the mean of its divisors is an integer number (27664).

2⁶⁴⁶⁸⁸⁴ 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 646884, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (995904).

646884 is an abundant number, since it is smaller than the sum of its proper divisors (1344924).

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

646884 is a wasteful number, since it uses less digits than its factorization.

646884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185 (or 180 counting only the distinct ones).

The product of its digits is 36864, while the sum is 36.

The square root of 646884 is about 804.2909921167. The cubic root of 646884 is about 86.4852681874.

The spelling of 646884 in words is "six hundred forty-six thousand, eight hundred eighty-four".