81186798 has 64 divisors (see below), whose sum is σ = 214368768. Its totient is φ = 19845120.

The previous prime is 81186751. The next prime is 81186821. The reversal of 81186798 is 89768118.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2686 + ... + 13022.

It is an arithmetic number, because the mean of its divisors is an integer number (3349512).

Almost surely, 2^81186798 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81186798, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107184384).

81186798 is an abundant number, since it is smaller than the sum of its proper divisors (133181970).

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

81186798 is a wasteful number, since it uses less digits than its factorization.

81186798 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10377.

The product of its digits is 193536, while the sum is 48.

The square root of 81186798 is about 9010.3716904465. The cubic root of 81186798 is about 433.0072198587.

The spelling of 81186798 in words is "eighty-one million, one hundred eighty-six thousand, seven hundred ninety-eight".