1161775991 has 2 divisors, whose sum is σ = 1161775992. Its totient is φ = 1161775990.

The previous prime is 1161775969. The next prime is 1161776003. The reversal of 1161775991 is 1995771611.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1161775991 - 2²² = 1157581687 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1161775921) 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, 580887995 + 580887996.

It is an arithmetic number, because the mean of its divisors is an integer number (580887996).

Almost surely, 2^1161775991 is an apocalyptic number.

1161775991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1161775991 is an equidigital number, since it uses as much as digits as its factorization.

1161775991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 119070, while the sum is 47.

The square root of 1161775991 is about 34084.8352057040. The cubic root of 1161775991 is about 1051.2535266346.

The spelling of 1161775991 in words is "one billion, one hundred sixty-one million, seven hundred seventy-five thousand, nine hundred ninety-one".