81075 has 24 divisors (see below), whose sum is σ = 142848. Its totient is φ = 40480.

The previous prime is 81071. The next prime is 81077. The reversal of 81075 is 57018.

81075 = 48² + 49² + ... + 70².

It is a happy number.

It is not a de Polignac number, because 81075 - 2² = 81071 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81071) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1702 + ... + 1748.

It is an arithmetic number, because the mean of its divisors is an integer number (5952).

2⁸¹⁰⁷⁵ is an apocalyptic number.

81075 is a deficient number, since it is larger than the sum of its proper divisors (61773).

81075 is a wasteful number, since it uses less digits than its factorization.

81075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 21.

The square root of 81075 is about 284.7367204981. The cubic root of 81075 is about 43.2808371524.

The spelling of 81075 in words is "eighty-one thousand, seventy-five".