It is a happy number.
The square root of 685584 is 828.
It is a d-powerful number, because it can be written as 6 + 85 + 52 + 58 + 86 + 42 .
It is a Duffinian number.
It is a nialpdrome in base 16.
It is an unprimeable number.
685584 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
2685584 is an apocalyptic number.
685584 is the 828-th square number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 685584
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
685584 is a wasteful number, since it uses less digits than its factorization.
685584 is an evil number, because the sum of its binary digits is even.
The cubic root of 685584 is about 88.1766424335.
Multiplying 685584 by its sum of digits (36), we get a square (24681024 = 49682).
685584 divided by its sum of digits (36) gives a square (19044 = 1382).
The spelling of 685584 in words is "six hundred eighty-five thousand, five hundred eighty-four".