669844 has 24 divisors (see below), whose sum is σ = 1370880. Its totient is φ = 280416.

The previous prime is 669839. The next prime is 669847. The reversal of 669844 is 448966.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1062 + ... + 1570.

It is an arithmetic number, because the mean of its divisors is an integer number (57120).

2⁶⁶⁹⁸⁴⁴ 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 669844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (685440).

669844 is an abundant number, since it is smaller than the sum of its proper divisors (701036).

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

669844 is a wasteful number, since it uses less digits than its factorization.

669844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 567 (or 565 counting only the distinct ones).

The product of its digits is 41472, while the sum is 37.

The square root of 669844 is about 818.4399794731. The cubic root of 669844 is about 87.4966093924.

The spelling of 669844 in words is "six hundred sixty-nine thousand, eight hundred forty-four".