81965936 has 40 divisors (see below), whose sum is σ = 171707760. Its totient is φ = 37679616.

The previous prime is 81965899. The next prime is 81965941. The reversal of 81965936 is 63956918.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 64475 + ... + 65733.

It is an arithmetic number, because the mean of its divisors is an integer number (4292694).

Almost surely, 2^81965936 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 81965936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85853880).

81965936 is an abundant number, since it is smaller than the sum of its proper divisors (89741824).

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

81965936 is a wasteful number, since it uses less digits than its factorization.

81965936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1593 (or 1587 counting only the distinct ones).

The product of its digits is 349920, while the sum is 47.

The square root of 81965936 is about 9053.5040730095. The cubic root of 81965936 is about 434.3879815384.

The spelling of 81965936 in words is "eighty-one million, nine hundred sixty-five thousand, nine hundred thirty-six".