161111191 has 2 divisors, whose sum is σ = 161111192. Its totient is φ = 161111190.

The previous prime is 161111183. The next prime is 161111213. The reversal of 161111191 is 191111161.

It is an a-pointer prime, because the next prime (161111213) can be obtained adding 161111191 to its sum of digits (22).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161111191 - 2³ = 161111183 is a prime.

161111191 is a strobogrammatic number because it is the same when read upside-down.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161111491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80555595 + 80555596.

It is an arithmetic number, because the mean of its divisors is an integer number (80555596).

Almost surely, 2^161111191 is an apocalyptic number.

161111191 is a deficient number, since it is larger than the sum of its proper divisors (1).

161111191 is an equidigital number, since it uses as much as digits as its factorization.

161111191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54, while the sum is 22.

The square root of 161111191 is about 12692.9583234170. The cubic root of 161111191 is about 544.1373902822.

The spelling of 161111191 in words is "one hundred sixty-one million, one hundred eleven thousand, one hundred ninety-one".