9997981 is digitally balanced in base 2 and base 8, because in such bases it contains all the possibile digits an equal number of times.
It is a sphenic number, since it is the product of 3 distinct primes.
It is a cyclic number.
It is a Duffinian number.
9997981 is strictly pandigital in base 8.
9997981 is a lucky number.
It is a congruent number.
Almost surely, 29997981 is an apocalyptic number.
It is an amenable number.
9997981 is a wasteful number, since it uses less digits than its factorization.
9997981 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 30443.
The square root of 9997981 is about 3161.9584121237. The cubic root of 9997981 is about 215.4289686818.
The spelling of 9997981 in words is "nine million, nine hundred ninety-seven thousand, nine hundred eighty-one".