81105 has 8 divisors (see below), whose sum is σ = 129792. Its totient is φ = 43248.

The previous prime is 81101. The next prime is 81119. The reversal of 81105 is 50118.

It is a happy number.

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

It is not a de Polignac number, because 81105 - 2² = 81101 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15), and also a Moran number because the ratio is a prime number: 5407 = 81105 / (8 + 1 + 1 + 0 + 5).

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (81101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2689 + ... + 2718.

It is an arithmetic number, because the mean of its divisors is an integer number (16224).

2⁸¹¹⁰⁵ is an apocalyptic number.

It is an amenable number.

81105 is a deficient number, since it is larger than the sum of its proper divisors (48687).

81105 is a wasteful number, since it uses less digits than its factorization.

81105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5415.

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 81105 is about 284.7893958700. The cubic root of 81105 is about 43.2861748644.

The spelling of 81105 in words is "eighty-one thousand, one hundred five".