1801812 has 12 divisors (see below), whose sum is σ = 4204256. Its totient is φ = 600600.

The previous prime is 1801781. The next prime is 1801817. The reversal of 1801812 is 2181081.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1801817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75064 + ... + 75087.

2^1801812 is an apocalyptic number.

1801812 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1801812 is an abundant number, since it is smaller than the sum of its proper divisors (2402444).

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

1801812 is a wasteful number, since it uses less digits than its factorization.

1801812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150158 (or 150156 counting only the distinct ones).

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

The square root of 1801812 is about 1342.3159091659. The cubic root of 1801812 is about 121.6848445557.

Adding to 1801812 its reverse (2181081), we get a palindrome (3982893).

The spelling of 1801812 in words is "one million, eight hundred one thousand, eight hundred twelve".