It is a happy number.
198404640 is a `hidden beast` number, since 1 + 9 + 8 + 4 + 0 + 4 + 640 = 666.
It is a tau number, because it is divible by the number of its divisors (288).
It is a congruent number.
It is an unprimeable number.
Almost surely, 2198404640 is an apocalyptic number.
198404640 is a gapful number since it is divisible by the number (10) 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 198404640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (401768640).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
198404640 is an frugal number, since it uses more digits than its factorization.
198404640 is an odious number, because the sum of its binary digits is odd.
The square root of 198404640 is about 14085.6181972961. The cubic root of 198404640 is about 583.2444410579.
The spelling of 198404640 in words is "one hundred ninety-eight million, four hundred four thousand, six hundred forty".