161775018 has 12 divisors (see below), whose sum is σ = 350512578. Its totient is φ = 53925000.

The previous prime is 161775017. The next prime is 161775041. The reversal of 161775018 is 810577161.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 156425049 + 5349969 = 12507^2 + 2313^2 .

It is not an unprimeable number, because it can be changed into a prime (161775017) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4493733 + ... + 4493768.

Almost surely, 2^161775018 is an apocalyptic number.

161775018 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

161775018 is an abundant number, since it is smaller than the sum of its proper divisors (188737560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161775018 is a wasteful number, since it uses less digits than its factorization.

161775018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8987509 (or 8987506 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 36.

The square root of 161775018 is about 12719.0808630184. The cubic root of 161775018 is about 544.8837032666.

The spelling of 161775018 in words is "one hundred sixty-one million, seven hundred seventy-five thousand, eighteen".