2191291 has 2 divisors, whose sum is σ = 2191292. Its totient is φ = 2191290.

The previous prime is 2191261. The next prime is 2191331. The reversal of 2191291 is 1921912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2191291 - 2¹⁵ = 2158523 is a prime.

2191291 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (2191261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1095645 + 1095646.

It is an arithmetic number, because the mean of its divisors is an integer number (1095646).

2^2191291 is an apocalyptic number.

2191291 is a deficient number, since it is larger than the sum of its proper divisors (1).

2191291 is an equidigital number, since it uses as much as digits as its factorization.

2191291 is an evil number, because the sum of its binary digits is even.

The product of its digits is 324, while the sum is 25.

The square root of 2191291 is about 1480.3009829085. The cubic root of 2191291 is about 129.8872987736.

The spelling of 2191291 in words is "two million, one hundred ninety-one thousand, two hundred ninety-one".