81571 has 8 divisors (see below), whose sum is σ = 95744. Its totient is φ = 68040.

The previous prime is 81569. The next prime is 81611. The reversal of 81571 is 17518.

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

It is not a de Polignac number, because 81571 - 2¹ = 81569 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81551) 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, 166 + ... + 436.

It is an arithmetic number, because the mean of its divisors is an integer number (11968).

2⁸¹⁵⁷¹ is an apocalyptic number.

81571 is a deficient number, since it is larger than the sum of its proper divisors (14173).

81571 is a wasteful number, since it uses less digits than its factorization.

81571 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321.

The product of its digits is 280, while the sum is 22.

The square root of 81571 is about 285.6063724779. The cubic root of 81571 is about 43.3689188295.

The spelling of 81571 in words is "eighty-one thousand, five hundred seventy-one".