291091 has 4 divisors (see below), whose sum is σ = 308232. Its totient is φ = 273952.

The previous prime is 291089. The next prime is 291101. The reversal of 291091 is 190192.

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 291091 - 2¹ = 291089 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

291091 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (291041) 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, 8545 + ... + 8578.

It is an arithmetic number, because the mean of its divisors is an integer number (77058).

2²⁹¹⁰⁹¹ is an apocalyptic number.

291091 is a deficient number, since it is larger than the sum of its proper divisors (17141).

291091 is a wasteful number, since it uses less digits than its factorization.

291091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17140.

The product of its (nonzero) digits is 162, while the sum is 22.

The square root of 291091 is about 539.5284978572. The cubic root of 291091 is about 66.2739607172.

The spelling of 291091 in words is "two hundred ninety-one thousand, ninety-one".