161911 has 2 divisors, whose sum is σ = 161912. Its totient is φ = 161910.

The previous prime is 161881. The next prime is 161921. The reversal of 161911 is 119161.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 161911 - 2⁵ = 161879 is a prime.

161911 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161921) 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, 80955 + 80956.

It is an arithmetic number, because the mean of its divisors is an integer number (80956).

2¹⁶¹⁹¹¹ is an apocalyptic number.

161911 is a deficient number, since it is larger than the sum of its proper divisors (1).

161911 is an equidigital number, since it uses as much as digits as its factorization.

161911 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 161911 is about 402.3816596218. The cubic root of 161911 is about 54.5036330098.

The spelling of 161911 in words is "one hundred sixty-one thousand, nine hundred eleven".