81955 has 8 divisors (see below), whose sum is σ = 101232. Its totient is φ = 63648.

The previous prime is 81953. The next prime is 81967. The reversal of 81955 is 55918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81955 - 2¹ = 81953 is a prime.

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

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37 + ... + 406.

It is an arithmetic number, because the mean of its divisors is an integer number (12654).

2⁸¹⁹⁵⁵ is an apocalyptic number.

81955 is a deficient number, since it is larger than the sum of its proper divisors (19277).

81955 is a wasteful number, since it uses less digits than its factorization.

81955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 485.

The product of its digits is 1800, while the sum is 28.

The square root of 81955 is about 286.2778370744. The cubic root of 81955 is about 43.4368661813.

The spelling of 81955 in words is "eighty-one thousand, nine hundred fifty-five".