It is a happy number.
51688 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
251688 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 51688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60480).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
51688 is a wasteful number, since it uses less digits than its factorization.
51688 is an evil number, because the sum of its binary digits is even.
The square root of 51688 is about 227.3499505168. The cubic root of 51688 is about 37.2503115449.
The spelling of 51688 in words is "fifty-one thousand, six hundred eighty-eight".