668724 has 48 divisors (see below), whose sum is σ = 1881600. Its totient is φ = 180576.

The previous prime is 668719. The next prime is 668737. The reversal of 668724 is 427866.

It is a congruent number.

It is an unprimeable number.

668724 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 15 ways as a sum of consecutive naturals, for example, 1387 + ... + 1805.

It is an arithmetic number, because the mean of its divisors is an integer number (39200).

2⁶⁶⁸⁷²⁴ 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 668724, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (940800).

668724 is an abundant number, since it is smaller than the sum of its proper divisors (1212876).

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

668724 is a wasteful number, since it uses less digits than its factorization.

668724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452 (or 450 counting only the distinct ones).

The product of its digits is 16128, while the sum is 33.

The square root of 668724 is about 817.7554646714. The cubic root of 668724 is about 87.4478165039.

The spelling of 668724 in words is "six hundred sixty-eight thousand, seven hundred twenty-four".