181345 has 4 divisors (see below), whose sum is σ = 217620. Its totient is φ = 145072.

The previous prime is 181303. The next prime is 181361. The reversal of 181345 is 543181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 543181 = 181 ⋅3001.

It can be written as a sum of positive squares in 2 ways, for example, as 134689 + 46656 = 367^2 + 216^2 .

It is a cyclic number.

It is not a de Polignac number, because 181345 - 2¹⁷ = 50273 is a prime.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 18130 + ... + 18139.

It is an arithmetic number, because the mean of its divisors is an integer number (54405).

2¹⁸¹³⁴⁵ is an apocalyptic number.

It is an amenable number.

181345 is a deficient number, since it is larger than the sum of its proper divisors (36275).

181345 is an equidigital number, since it uses as much as digits as its factorization.

181345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36274.

The product of its digits is 480, while the sum is 22.

The square root of 181345 is about 425.8462163739. The cubic root of 181345 is about 56.6024455069.

The spelling of 181345 in words is "one hundred eighty-one thousand, three hundred forty-five".