646704 has 50 divisors (see below), whose sum is σ = 1875500. Its totient is φ = 215136.

The previous prime is 646687. The next prime is 646721. The reversal of 646704 is 407646.

646704 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (646687) and next prime (646721).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1047 + ... + 1545.

It is an arithmetic number, because the mean of its divisors is an integer number (37510).

2⁶⁴⁶⁷⁰⁴ 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 646704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (937750).

646704 is an abundant number, since it is smaller than the sum of its proper divisors (1228796).

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

646704 is a wasteful number, since it uses less digits than its factorization.

646704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519 (or 504 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 646704 is about 804.1790845328. The cubic root of 646704 is about 86.4772457329.

The spelling of 646704 in words is "six hundred forty-six thousand, seven hundred four".