181812 has 24 divisors (see below), whose sum is σ = 431200. Its totient is φ = 59616.

The previous prime is 181789. The next prime is 181813. The reversal of 181812 is 218181.

It is an alternating number because its digits alternate between odd and even.

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 181812.

It is not an unprimeable number, because it can be changed into a prime (181813) by changing a digit.

181812 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1239 + ... + 1377.

2¹⁸¹⁸¹² is an apocalyptic number.

181812 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

181812 is an abundant number, since it is smaller than the sum of its proper divisors (249388).

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

181812 is a wasteful number, since it uses less digits than its factorization.

181812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255 (or 253 counting only the distinct ones).

The product of its digits is 128, while the sum is 21.

The square root of 181812 is about 426.3941838252. The cubic root of 181812 is about 56.6509914351.

Adding to 181812 its reverse (218181), we get a palindrome (399993).

It can be divided in two parts, 1818 and 12, that added together give a triangular number (1830 = T₆₀).

The spelling of 181812 in words is "one hundred eighty-one thousand, eight hundred twelve".