81936 has 30 divisors (see below), whose sum is σ = 229710. Its totient is φ = 27264.

The previous prime is 81931. The next prime is 81937. The reversal of 81936 is 63918.

It can be written as a sum of positive squares in only one way, i.e., 57600 + 24336 = 240^2 + 156^2 .

It is a nude number because it is divisible by every one of its digits.

It is one of the 548 Lynch-Bell numbers.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 81936.

It is not an unprimeable number, because it can be changed into a prime (81931) by changing a digit.

81936 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 141 + ... + 428.

It is an arithmetic number, because the mean of its divisors is an integer number (7657).

2⁸¹⁹³⁶ is an apocalyptic number.

It is an amenable number.

81936 is an abundant number, since it is smaller than the sum of its proper divisors (147774).

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

81936 is a wasteful number, since it uses less digits than its factorization.

81936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583 (or 574 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 81936 is about 286.2446506050. The cubic root of 81936 is about 43.4335091998.

The spelling of 81936 in words is "eighty-one thousand, nine hundred thirty-six".