It is a happy number.
It is an Ulam number.
It is a nialpdrome in base 10.
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 99540.
It is an unprimeable number.
99540 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
299540 is an apocalyptic number.
99540 is a gapful number since it is divisible by the number (90) 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 99540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174720).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
99540 is a wasteful number, since it uses less digits than its factorization.
99540 is an odious number, because the sum of its binary digits is odd.
The square root of 99540 is about 315.4996038032. The cubic root of 99540 is about 46.3446078987.
The spelling of 99540 in words is "ninety-nine thousand, five hundred forty".