It is a happy number.
It is a tau number, because it is divible by the number of its divisors (96).
It is a congruent number.
405216 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
2405216 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 405216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (685440).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
405216 is a wasteful number, since it uses less digits than its factorization.
405216 is an odious number, because the sum of its binary digits is odd.
The square root of 405216 is about 636.5657860740. The cubic root of 405216 is about 73.9995130233. Note that the first 3 decimals are identical.
The spelling of 405216 in words is "four hundred five thousand, two hundred sixteen".