27971 has 4 divisors (see below), whose sum is σ = 28392. Its totient is φ = 27552.

The previous prime is 27967. The next prime is 27983. The reversal of 27971 is 17972.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 27971 - 2² = 27967 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 27971.

It is not an unprimeable number, because it can be changed into a prime (27901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86 + ... + 251.

It is an arithmetic number, because the mean of its divisors is an integer number (7098).

2²⁷⁹⁷¹ is an apocalyptic number.

27971 is a deficient number, since it is larger than the sum of its proper divisors (421).

27971 is an equidigital number, since it uses as much as digits as its factorization.

27971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 420.

The product of its digits is 882, while the sum is 26.

The square root of 27971 is about 167.2453287838. The cubic root of 27971 is about 30.3554026355.

Subtracting from 27971 its reverse (17972), we obtain a palindrome (9999).

The spelling of 27971 in words is "twenty-seven thousand, nine hundred seventy-one".