81768 has 16 divisors (see below), whose sum is σ = 204480.
Its totient is φ = 27248.
The previous prime is 81761. The next prime is 81769. The reversal of 81768 is 86718.
Subtracting 81768 from its reverse (86718), we obtain a triangular number (4950 = T99).
It is not an unprimeable number, because it can be changed into a prime (81761) by changing a digit.
81768 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1680 + ... + 1727.
It is an arithmetic number, because the mean of its divisors is an integer number (12780).
281768 is an apocalyptic number.
It is an amenable number.
81768 is an abundant number, since it is smaller than the sum of its proper divisors (122712).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (102240).
81768 is a wasteful number, since it uses less digits than its factorization.
81768 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 3416 (or 3412 counting only the distinct ones).
The product of its digits is 2688, while the sum is 30.
The square root of 81768 is about 285.9510447612.
The cubic root of 81768 is about 43.4038038105.
The spelling of 81768 in words is "eighty-one thousand, seven hundred sixty-eight".