161918 has 8 divisors (see below), whose sum is σ = 255720. Its totient is φ = 76680.

The previous prime is 161911. The next prime is 161921. The reversal of 161918 is 819161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161911) by changing a digit.

161918 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 in 3 ways as a sum of consecutive naturals, for example, 2093 + ... + 2168.

It is an arithmetic number, because the mean of its divisors is an integer number (31965).

2¹⁶¹⁹¹⁸ is an apocalyptic number.

161918 is a deficient number, since it is larger than the sum of its proper divisors (93802).

161918 is a wasteful number, since it uses less digits than its factorization.

161918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4282.

The product of its digits is 432, while the sum is 26.

The square root of 161918 is about 402.3903577374. The cubic root of 161918 is about 54.5044184617.

The spelling of 161918 in words is "one hundred sixty-one thousand, nine hundred eighteen".