679644 has 96 divisors (see below), whose sum is σ = 2150400. Its totient is φ = 181440.

The previous prime is 679639. The next prime is 679669. The reversal of 679644 is 446976.

679644 is a `hidden beast` number, since 6 + 7 + 9 + 644 = 666.

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

It is a nude number because it is divisible by every one of its digits.

Its product of digits (36288) is a multiple of the sum of its prime divisors (72).

It is a junction number, because it is equal to n+sod(n) for n = 679599 and 679608.

It is a congruent number.

It is an unprimeable number.

679644 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 21909 + ... + 21939.

It is an arithmetic number, because the mean of its divisors is an integer number (22400).

2⁶⁷⁹⁶⁴⁴ 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 679644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1075200).

679644 is an abundant number, since it is smaller than the sum of its proper divisors (1470756).

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

679644 is a wasteful number, since it uses less digits than its factorization.

679644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80 (or 72 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 679644 is about 824.4052401580. The cubic root of 679644 is about 87.9212449667.

The spelling of 679644 in words is "six hundred seventy-nine thousand, six hundred forty-four".