291491 has 2 divisors, whose sum is σ = 291492. Its totient is φ = 291490.

The previous prime is 291481. The next prime is 291503. The reversal of 291491 is 194192.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 291491 - 2¹⁸ = 29347 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 291491.

It is not a weakly prime, because it can be changed into another prime (291481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145745 + 145746.

It is an arithmetic number, because the mean of its divisors is an integer number (145746).

2²⁹¹⁴⁹¹ is an apocalyptic number.

291491 is a deficient number, since it is larger than the sum of its proper divisors (1).

291491 is an equidigital number, since it uses as much as digits as its factorization.

291491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648, while the sum is 26.

The square root of 291491 is about 539.8990646408. The cubic root of 291491 is about 66.3043034060.

The spelling of 291491 in words is "two hundred ninety-one thousand, four hundred ninety-one".