1291139 has 2 divisors, whose sum is σ = 1291140. Its totient is φ = 1291138.

The previous prime is 1291117. The next prime is 1291153. The reversal of 1291139 is 9311921.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1291139 - 2¹⁶ = 1225603 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1291159) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645569 + 645570.

It is an arithmetic number, because the mean of its divisors is an integer number (645570).

2^1291139 is an apocalyptic number.

1291139 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291139 is an equidigital number, since it uses as much as digits as its factorization.

1291139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 486, while the sum is 26.

The square root of 1291139 is about 1136.2829753191. The cubic root of 1291139 is about 108.8907527023.

The spelling of 1291139 in words is "one million, two hundred ninety-one thousand, one hundred thirty-nine".