81716868 has 72 divisors (see below), whose sum is σ = 219098880. Its totient is φ = 25634880.

The previous prime is 81716851. The next prime is 81716897. The reversal of 81716868 is 86861718.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40303 + ... + 42281.

It is an arithmetic number, because the mean of its divisors is an integer number (3043040).

Almost surely, 2^81716868 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 81716868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109549440).

81716868 is an abundant number, since it is smaller than the sum of its proper divisors (137382012).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81716868 is a wasteful number, since it uses less digits than its factorization.

81716868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2057 (or 2052 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

The square root of 81716868 is about 9039.7382705474. The cubic root of 81716868 is about 433.9475468756.

The spelling of 81716868 in words is "eighty-one million, seven hundred sixteen thousand, eight hundred sixty-eight".