191916161 has 2 divisors, whose sum is σ = 191916162. Its totient is φ = 191916160.

The previous prime is 191916143. The next prime is 191916173. The reversal of 191916161 is 161619191.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 183765136 + 8151025 = 13556^2 + 2855^2 .

It is an emirp because it is prime and its reverse (161619191) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191916161 is a prime.

191916161 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 (191916661) 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, 95958080 + 95958081.

It is an arithmetic number, because the mean of its divisors is an integer number (95958081).

Almost surely, 2^191916161 is an apocalyptic number.

It is an amenable number.

191916161 is a deficient number, since it is larger than the sum of its proper divisors (1).

191916161 is an equidigital number, since it uses as much as digits as its factorization.

191916161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2916, while the sum is 35.

The square root of 191916161 is about 13853.3808508970. The cubic root of 191916161 is about 576.8158459244.

It can be divided in two parts, 19191 and 6161, that added together give a palindrome (25352).

The spelling of 191916161 in words is "one hundred ninety-one million, nine hundred sixteen thousand, one hundred sixty-one".