191871 has 6 divisors (see below), whose sum is σ = 277160. Its totient is φ = 127908.

The previous prime is 191861. The next prime is 191899. The reversal of 191871 is 178191.

It is not a de Polignac number, because 191871 - 2¹¹ = 189823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191801) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10651 + ... + 10668.

2¹⁹¹⁸⁷¹ is an apocalyptic number.

191871 is a deficient number, since it is larger than the sum of its proper divisors (85289).

191871 is a wasteful number, since it uses less digits than its factorization.

191871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21325 (or 21322 counting only the distinct ones).

The product of its digits is 504, while the sum is 27.

The square root of 191871 is about 438.0308208334. The cubic root of 191871 is about 57.6770597652.

Subtracting from 191871 its sum of digits (27), we obtain a square (191844 = 438²).

The spelling of 191871 in words is "one hundred ninety-one thousand, eight hundred seventy-one".