491871 has 8 divisors (see below), whose sum is σ = 661504. Its totient is φ = 325080.

The previous prime is 491867. The next prime is 491873. The reversal of 491871 is 178194.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 491871 - 2² = 491867 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 (491873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 265 + ... + 1026.

It is an arithmetic number, because the mean of its divisors is an integer number (82688).

2⁴⁹¹⁸⁷¹ is an apocalyptic number.

491871 is a deficient number, since it is larger than the sum of its proper divisors (169633).

491871 is a wasteful number, since it uses less digits than its factorization.

491871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1421.

The product of its digits is 2016, while the sum is 30.

The square root of 491871 is about 701.3351552575. The cubic root of 491871 is about 78.9375675085.

The spelling of 491871 in words is "four hundred ninety-one thousand, eight hundred seventy-one".