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 999960.
2999960 is an apocalyptic number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 999960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1617840).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
999960 is a wasteful number, since it uses less digits than its factorization.
999960 is an evil number, because the sum of its binary digits is even.
The square root of 999960 is about 999.9799998000. The cubic root of 999960 is about 99.9986666489.
The spelling of 999960 in words is "nine hundred ninety-nine thousand, nine hundred sixty".