191161 has 2 divisors, whose sum is σ = 191162. Its totient is φ = 191160.

The previous prime is 191143. The next prime is 191173. The reversal of 191161 is 161191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 189225 + 1936 = 435^2 + 44^2 .

It is a cyclic number.

It is not a de Polignac number, because 191161 - 2⁷ = 191033 is a prime.

191161 is a strobogrammatic number because it is the same when read upside-down.

It is not a weakly prime, because it can be changed into another prime (191141) 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, 95580 + 95581.

It is an arithmetic number, because the mean of its divisors is an integer number (95581).

2¹⁹¹¹⁶¹ is an apocalyptic number.

It is an amenable number.

191161 is a deficient number, since it is larger than the sum of its proper divisors (1).

191161 is an equidigital number, since it uses as much as digits as its factorization.

191161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54, while the sum is 19.

The square root of 191161 is about 437.2196244452. The cubic root of 191161 is about 57.6058290461.

The spelling of 191161 in words is "one hundred ninety-one thousand, one hundred sixty-one".