1171127891 has 2 divisors, whose sum is σ = 1171127892. Its totient is φ = 1171127890.

The previous prime is 1171127887. The next prime is 1171127897. The reversal of 1171127891 is 1987211711.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1171127891 - 2² = 1171127887 is a prime.

It is not a weakly prime, because it can be changed into another prime (1171127897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 585563945 + 585563946.

It is an arithmetic number, because the mean of its divisors is an integer number (585563946).

Almost surely, 2^1171127891 is an apocalyptic number.

1171127891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1171127891 is an equidigital number, since it uses as much as digits as its factorization.

1171127891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7056, while the sum is 38.

The square root of 1171127891 is about 34221.7458788999. The cubic root of 1171127891 is about 1054.0667355940.

The spelling of 1171127891 in words is "one billion, one hundred seventy-one million, one hundred twenty-seven thousand, eight hundred ninety-one".