1812005 has 16 divisors (see below), whose sum is σ = 2385264. Its totient is φ = 1313280.

The previous prime is 1811993. The next prime is 1812037. The reversal of 1812005 is 5002181.

It can be written as a sum of positive squares in 8 ways, for example, as 229441 + 1582564 = 479^2 + 1258^2 .

It is not a de Polignac number, because 1812005 - 2¹⁰ = 1810981 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3737 + ... + 4193.

It is an arithmetic number, because the mean of its divisors is an integer number (149079).

2^1812005 is an apocalyptic number.

It is an amenable number.

1812005 is a deficient number, since it is larger than the sum of its proper divisors (573259).

1812005 is a wasteful number, since it uses less digits than its factorization.

1812005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 536.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 1812005 is about 1346.1073508454. The cubic root of 1812005 is about 121.9138736393.

Adding to 1812005 its reverse (5002181), we get a palindrome (6814186).

The spelling of 1812005 in words is "one million, eight hundred twelve thousand, five".