1291111 has 2 divisors, whose sum is σ = 1291112. Its totient is φ = 1291110.

The previous prime is 1291079. The next prime is 1291117. The reversal of 1291111 is 1111921.

It is a strong prime.

It is an emirp because it is prime and its reverse (1111921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1291111 - 2⁵ = 1291079 is a prime.

It is a super-2 number, since 2×1291111² = 3333935228642, which contains 22 as substring.

1291111 is a modest number, since divided by 1111 gives 129 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645555 + 645556.

It is an arithmetic number, because the mean of its divisors is an integer number (645556).

2^1291111 is an apocalyptic number.

1291111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291111 is an equidigital number, since it uses as much as digits as its factorization.

1291111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18, while the sum is 16.

The square root of 1291111 is about 1136.2706543777. The cubic root of 1291111 is about 108.8899655515.

The spelling of 1291111 in words is "one million, two hundred ninety-one thousand, one hundred eleven".