668400 has 60 divisors (see below), whose sum is σ = 2144952. Its totient is φ = 177920.

The previous prime is 668347. The next prime is 668407. The reversal of 668400 is 4866.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668407) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 922 + ... + 1478.

2⁶⁶⁸⁴⁰⁰ is an apocalyptic number.

668400 is a gapful number since it is divisible by the number (60) 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 668400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1072476).

668400 is an abundant number, since it is smaller than the sum of its proper divisors (1476552).

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

668400 is a wasteful number, since it uses less digits than its factorization.

668400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578 (or 567 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 668400 is about 817.5573374388. The cubic root of 668400 is about 87.4336912596.

The spelling of 668400 in words is "six hundred sixty-eight thousand, four hundred".