291871 has 4 divisors (see below), whose sum is σ = 297432. Its totient is φ = 286312.

The previous prime is 291869. The next prime is 291877. The reversal of 291871 is 178192.

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 291871 - 2¹ = 291869 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 (291877) 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, 2701 + ... + 2806.

It is an arithmetic number, because the mean of its divisors is an integer number (74358).

2²⁹¹⁸⁷¹ is an apocalyptic number.

291871 is a deficient number, since it is larger than the sum of its proper divisors (5561).

291871 is an equidigital number, since it uses as much as digits as its factorization.

291871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5560.

The product of its digits is 1008, while the sum is 28.

The square root of 291871 is about 540.2508676532. The cubic root of 291871 is about 66.3331032598. Note that the first 3 decimals are identical.

The spelling of 291871 in words is "two hundred ninety-one thousand, eight hundred seventy-one".