181099 has 4 divisors (see below), whose sum is σ = 183064. Its totient is φ = 179136.

The previous prime is 181087. The next prime is 181123. The reversal of 181099 is 990181.

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

It is a cyclic number.

It is not a de Polignac number, because 181099 - 2¹¹ = 179051 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 837 + ... + 1030.

It is an arithmetic number, because the mean of its divisors is an integer number (45766).

2¹⁸¹⁰⁹⁹ is an apocalyptic number.

181099 is a deficient number, since it is larger than the sum of its proper divisors (1965).

181099 is an equidigital number, since it uses as much as digits as its factorization.

181099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1964.

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 181099 is about 425.5572816907. The cubic root of 181099 is about 56.5768396129.

The spelling of 181099 in words is "one hundred eighty-one thousand, ninety-nine".