161886173 has 4 divisors (see below), whose sum is σ = 163318908. Its totient is φ = 160453440.

The previous prime is 161886169. The next prime is 161886199. The reversal of 161886173 is 371688161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 49589764 + 112296409 = 7042^2 + 10597^2 .

It is a cyclic number.

It is not a de Polignac number, because 161886173 - 2² = 161886169 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 161886173.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161882173) 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 3 ways as a sum of consecutive naturals, for example, 716198 + ... + 716423.

It is an arithmetic number, because the mean of its divisors is an integer number (40829727).

Almost surely, 2^161886173 is an apocalyptic number.

It is an amenable number.

161886173 is a deficient number, since it is larger than the sum of its proper divisors (1432735).

161886173 is a wasteful number, since it uses less digits than its factorization.

161886173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1432734.

The product of its digits is 48384, while the sum is 41.

The square root of 161886173 is about 12723.4497287489. The cubic root of 161886173 is about 545.0084705358.

The spelling of 161886173 in words is "one hundred sixty-one million, eight hundred eighty-six thousand, one hundred seventy-three".