It is an unprimeable number.
Almost surely, 281698816 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 81698816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81702021).
81698816 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
81698816 is an frugal number, since it uses more digits than its factorization.
81698816 is an odious number, because the sum of its binary digits is odd.
The square root of 81698816 is about 9038.7397351622. The cubic root of 81698816 is about 433.9155902012.
The spelling of 81698816 in words is "eighty-one million, six hundred ninety-eight thousand, eight hundred sixteen".