1115221391 has 2 divisors, whose sum is σ = 1115221392. Its totient is φ = 1115221390.

The previous prime is 1115221339. The next prime is 1115221399. The reversal of 1115221391 is 1931225111.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1115221391 - 2²² = 1111027087 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1115221391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1115221399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 557610695 + 557610696.

It is an arithmetic number, because the mean of its divisors is an integer number (557610696).

Almost surely, 2^1115221391 is an apocalyptic number.

1115221391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1115221391 is an equidigital number, since it uses as much as digits as its factorization.

1115221391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 540, while the sum is 26.

The square root of 1115221391 is about 33394.9306182840. The cubic root of 1115221391 is about 1037.0197565628.

The spelling of 1115221391 in words is "one billion, one hundred fifteen million, two hundred twenty-one thousand, three hundred ninety-one".