667440 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
2667440 is an apocalyptic number.
667440 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 667440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1170312).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
667440 is a wasteful number, since it uses less digits than its factorization.
667440 is an odious number, because the sum of its binary digits is odd.
The square root of 667440 is about 816.9700116895. The cubic root of 667440 is about 87.3918118657.
The spelling of 667440 in words is "six hundred sixty-seven thousand, four hundred forty".