161011191 has 24 divisors (see below), whose sum is σ = 240453360. Its totient is φ = 95729920.

The previous prime is 161011189. The next prime is 161011211. The reversal of 161011191 is 191110161.

It is not a de Polignac number, because 161011191 - 2¹ = 161011189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161011121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15055 + ... + 23423.

It is an arithmetic number, because the mean of its divisors is an integer number (10018890).

Almost surely, 2^161011191 is an apocalyptic number.

161011191 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

161011191 is a deficient number, since it is larger than the sum of its proper divisors (79442169).

161011191 is a wasteful number, since it uses less digits than its factorization.

161011191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8447 (or 8436 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 21.

The square root of 161011191 is about 12689.0185199644. The cubic root of 161011191 is about 544.0247868878.

The spelling of 161011191 in words is "one hundred sixty-one million, eleven thousand, one hundred ninety-one".