161191365 has 16 divisors (see below), whose sum is σ = 273077568. Its totient is φ = 80911616.

The previous prime is 161191361. The next prime is 161191379. The reversal of 161191365 is 563191161.

It is a cyclic number.

It is not a de Polignac number, because 161191365 - 2² = 161191361 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161191361) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 315807 + ... + 316316.

It is an arithmetic number, because the mean of its divisors is an integer number (17067348).

Almost surely, 2^161191365 is an apocalyptic number.

161191365 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161191365 is a deficient number, since it is larger than the sum of its proper divisors (111886203).

161191365 is a wasteful number, since it uses less digits than its factorization.

161191365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 632148.

The product of its digits is 4860, while the sum is 33.

The square root of 161191365 is about 12696.1161384102. The cubic root of 161191365 is about 544.2276352787.

The spelling of 161191365 in words is "one hundred sixty-one million, one hundred ninety-one thousand, three hundred sixty-five".