81956 has 12 divisors (see below), whose sum is σ = 163968. Its totient is φ = 35112.

The previous prime is 81953. The next prime is 81967. The reversal of 81956 is 65918.

81956 is an admirable number.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 81956.

It is not an unprimeable number, because it can be changed into a prime (81953) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1436 + ... + 1491.

It is an arithmetic number, because the mean of its divisors is an integer number (13664).

2⁸¹⁹⁵⁶ is an apocalyptic number.

It is an amenable number.

81956 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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 (81984).

81956 is a wasteful number, since it uses less digits than its factorization.

81956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2938 (or 2936 counting only the distinct ones).

The product of its digits is 2160, while the sum is 29.

The square root of 81956 is about 286.2795836241. The cubic root of 81956 is about 43.4370428501.

The spelling of 81956 in words is "eighty-one thousand, nine hundred fifty-six".