291243 has 4 divisors (see below), whose sum is σ = 388328. Its totient is φ = 194160.

The previous prime is 291217. The next prime is 291253. The reversal of 291243 is 342192.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 291243 - 2⁸ = 290987 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (291253) 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, 48538 + ... + 48543.

It is an arithmetic number, because the mean of its divisors is an integer number (97082).

2²⁹¹²⁴³ is an apocalyptic number.

291243 is a deficient number, since it is larger than the sum of its proper divisors (97085).

291243 is an equidigital number, since it uses as much as digits as its factorization.

291243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97084.

The product of its digits is 432, while the sum is 21.

The square root of 291243 is about 539.6693432093. The cubic root of 291243 is about 66.2854942114.

The spelling of 291243 in words is "two hundred ninety-one thousand, two hundred forty-three".