181000 has 32 divisors (see below), whose sum is σ = 425880. Its totient is φ = 72000.

The previous prime is 180959. The next prime is 181001. The reversal of 181000 is 181.

It can be written as a sum of positive squares in 4 ways, for example, as 9604 + 171396 = 98^2 + 414^2 .

It is a super-2 number, since 2×181000² = 65522000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

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 7 ways as a sum of consecutive naturals, for example, 910 + ... + 1090.

2¹⁸¹⁰⁰⁰ is an apocalyptic number.

181000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 181000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212940).

181000 is an abundant number, since it is smaller than the sum of its proper divisors (244880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

181000 is a wasteful number, since it uses less digits than its factorization.

181000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202 (or 188 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 181000 is about 425.4409477237. The cubic root of 181000 is about 56.5665282582.

Adding to 181000 its reverse (181), we get a palindrome (181181).

181000 divided by its reverse (181) gives a cube (1000 = 10³).

The spelling of 181000 in words is "one hundred eighty-one thousand".