161800018 has 8 divisors (see below), whose sum is σ = 243105660. Its totient is φ = 80764800.

The previous prime is 161799997. The next prime is 161800073. The reversal of 161800018 is 810008161.

It is a happy number.

161800018 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 147306769 + 14493249 = 12137^2 + 3807^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 161799965 and 161800001.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 66103 + ... + 68506.

Almost surely, 2^161800018 is an apocalyptic number.

161800018 is a deficient number, since it is larger than the sum of its proper divisors (81305642).

161800018 is a wasteful number, since it uses less digits than its factorization.

161800018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135212.

The product of its (nonzero) digits is 384, while the sum is 25.

The square root of 161800018 is about 12720.0636004699. The cubic root of 161800018 is about 544.9117697982.

Adding to 161800018 its reverse (810008161), we get a palindrome (971808179).

The spelling of 161800018 in words is "one hundred sixty-one million, eight hundred thousand, eighteen".