13971 has 4 divisors (see below), whose sum is σ = 18632. Its totient is φ = 9312.

The previous prime is 13967. The next prime is 13997. The reversal of 13971 is 17931.

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

It is not a de Polignac number, because 13971 - 2² = 13967 is a prime.

It is a D-number.

It is a Duffinian number.

It is a nialpdrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (13901) 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, 2326 + ... + 2331.

It is an arithmetic number, because the mean of its divisors is an integer number (4658).

2¹³⁹⁷¹ is an apocalyptic number.

13971 is a deficient number, since it is larger than the sum of its proper divisors (4661).

13971 is an equidigital number, since it uses as much as digits as its factorization.

13971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4660.

The product of its digits is 189, while the sum is 21.

The square root of 13971 is about 118.1989847672. The cubic root of 13971 is about 24.0847696795.

It can be divided in two parts, 139 and 71, that added together give a triangular number (210 = T₂₀).

The spelling of 13971 in words is "thirteen thousand, nine hundred seventy-one".