673664 has 32 divisors (see below), whose sum is σ = 1417800. Its totient is φ = 317952.

The previous prime is 673649. The next prime is 673667. The reversal of 673664 is 466376.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a self number, because there is not a number n which added to its sum of digits gives 673664.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 673664.

It is not an unprimeable number, because it can be changed into a prime (673667) by changing a digit.

673664 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2294 + ... + 2570.

2⁶⁷³⁶⁶⁴ is an apocalyptic number.

673664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 673664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (708900).

673664 is an abundant number, since it is smaller than the sum of its proper divisors (744136).

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

673664 is a wasteful number, since it uses less digits than its factorization.

673664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310 (or 298 counting only the distinct ones).

The product of its digits is 18144, while the sum is 32.

The square root of 673664 is about 820.7703698356. The cubic root of 673664 is about 87.6626200300.

The spelling of 673664 in words is "six hundred seventy-three thousand, six hundred sixty-four".