291891 has 8 divisors (see below), whose sum is σ = 392400. Its totient is φ = 192992.

The previous prime is 291887. The next prime is 291899. The reversal of 291891 is 198192.

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

It is a cyclic number.

It is not a de Polignac number, because 291891 - 2² = 291887 is a prime.

291891 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 291891.

It is not an unprimeable number, because it can be changed into a prime (291899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121 + ... + 773.

It is an arithmetic number, because the mean of its divisors is an integer number (49050).

2²⁹¹⁸⁹¹ is an apocalyptic number.

291891 is a deficient number, since it is larger than the sum of its proper divisors (100509).

291891 is a wasteful number, since it uses less digits than its factorization.

291891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 805.

The product of its digits is 1296, while the sum is 30.

The square root of 291891 is about 540.2693772555. The cubic root of 291891 is about 66.3346183489.

The spelling of 291891 in words is "two hundred ninety-one thousand, eight hundred ninety-one".