81771 has 8 divisors (see below), whose sum is σ = 110544. Its totient is φ = 53760.

The previous prime is 81769. The next prime is 81773. The reversal of 81771 is 17718.

It is an interprime number because it is at equal distance from previous prime (81769) and next prime (81773).

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

It is not a de Polignac number, because 81771 - 2¹ = 81769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81773) 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, 151 + ... + 431.

It is an arithmetic number, because the mean of its divisors is an integer number (13818).

2⁸¹⁷⁷¹ is an apocalyptic number.

81771 is a deficient number, since it is larger than the sum of its proper divisors (28773).

81771 is a wasteful number, since it uses less digits than its factorization.

81771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381.

The product of its digits is 392, while the sum is 24.

The square root of 81771 is about 285.9562903662. The cubic root of 81771 is about 43.4043346205.

It can be divided in two parts, 817 and 71, that added together give a palindrome (888).

The spelling of 81771 in words is "eighty-one thousand, seven hundred seventy-one".