181005 has 16 divisors (see below), whose sum is σ = 316224. Its totient is φ = 87680.

The previous prime is 181003. The next prime is 181019. The reversal of 181005 is 500181.

It is a happy number.

181005 is nontrivially palindromic in base 2.

It is not a de Polignac number, because 181005 - 2¹ = 181003 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 181005.

It is not an unprimeable number, because it can be changed into a prime (181001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 384 + ... + 713.

It is an arithmetic number, because the mean of its divisors is an integer number (19764).

2¹⁸¹⁰⁰⁵ is an apocalyptic number.

181005 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

181005 is a deficient number, since it is larger than the sum of its proper divisors (135219).

181005 is a wasteful number, since it uses less digits than its factorization.

181005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1116.

The product of its (nonzero) digits is 40, while the sum is 15.

The square root of 181005 is about 425.4468239393. The cubic root of 181005 is about 56.5670491239.

Adding to 181005 its reverse (500181), we get a palindrome (681186).

The spelling of 181005 in words is "one hundred eighty-one thousand, five".