201812 has 12 divisors (see below), whose sum is σ = 380436. Its totient is φ = 93120.

The previous prime is 201809. The next prime is 201821. The reversal of 201812 is 218102.

It can be written as a sum of positive squares in 2 ways, for example, as 75076 + 126736 = 274^2 + 356^2 .

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 201812.

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, 1889 + ... + 1992.

It is an arithmetic number, because the mean of its divisors is an integer number (31703).

2²⁰¹⁸¹² is an apocalyptic number.

It is an amenable number.

201812 is a deficient number, since it is larger than the sum of its proper divisors (178624).

201812 is a wasteful number, since it uses less digits than its factorization.

201812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3898 (or 3896 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 201812 is about 449.2349051443. The cubic root of 201812 is about 58.6564347399.

Adding to 201812 its reverse (218102), we get a palindrome (419914).

Subtracting 201812 from its reverse (218102), we obtain a triangular number (16290 = T₁₈₀).

The spelling of 201812 in words is "two hundred one thousand, eight hundred twelve".