111971 has 4 divisors (see below), whose sum is σ = 114744. Its totient is φ = 109200.

The previous prime is 111959. The next prime is 111973. The reversal of 111971 is 179111.

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 111971 - 2¹⁰ = 110947 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 111971.

It is not an unprimeable number, because it can be changed into a prime (111973) 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, 1325 + ... + 1406.

It is an arithmetic number, because the mean of its divisors is an integer number (28686).

2¹¹¹⁹⁷¹ is an apocalyptic number.

111971 is a deficient number, since it is larger than the sum of its proper divisors (2773).

111971 is an equidigital number, since it uses as much as digits as its factorization.

111971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2772.

The product of its digits is 63, while the sum is 20.

The square root of 111971 is about 334.6206807715. The cubic root of 111971 is about 48.1986845598.

The spelling of 111971 in words is "one hundred eleven thousand, nine hundred seventy-one".