181285 has 8 divisors (see below), whose sum is σ = 234360. Its totient is φ = 133824.

The previous prime is 181283. The next prime is 181297. The reversal of 181285 is 582181.

It can be written as a sum of positive squares in 4 ways, for example, as 6561 + 174724 = 81^2 + 418^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 181285 - 2¹ = 181283 is a prime.

It is an Ulam number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1330 + ... + 1459.

It is an arithmetic number, because the mean of its divisors is an integer number (29295).

2¹⁸¹²⁸⁵ is an apocalyptic number.

It is an amenable number.

181285 is a deficient number, since it is larger than the sum of its proper divisors (53075).

181285 is a wasteful number, since it uses less digits than its factorization.

181285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2807.

The product of its digits is 640, while the sum is 25.

The square root of 181285 is about 425.7757625793. The cubic root of 181285 is about 56.5962023032.

The spelling of 181285 in words is "one hundred eighty-one thousand, two hundred eighty-five".