It is a sphenic number, since it is the product of 3 distinct primes.
It is a cyclic number.
It is a plaindrome in base 8 and base 14.
It is a nialpdrome in base 16.
It is a zygodrome in base 16.
It is a congruent number.
247991 is an apocalyptic number.
47991 is a wasteful number, since it uses less digits than its factorization.
47991 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 961.
The square root of 47991 is about 219.0684824433. The cubic root of 47991 is about 36.3401403139.
Subtracting from 47991 its sum of digits (30), we obtain a square (47961 = 2192).
The spelling of 47991 in words is "forty-seven thousand, nine hundred ninety-one".