1812643 has 4 divisors (see below), whose sum is σ = 2071600. Its totient is φ = 1553688.

The previous prime is 1812623. The next prime is 1812661. The reversal of 1812643 is 3462181.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1812643 - 2⁵ = 1812611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1812623) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 129468 + ... + 129481.

It is an arithmetic number, because the mean of its divisors is an integer number (517900).

2^1812643 is an apocalyptic number.

1812643 is a deficient number, since it is larger than the sum of its proper divisors (258957).

1812643 is an equidigital number, since it uses as much as digits as its factorization.

1812643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258956.

The product of its digits is 1152, while the sum is 25.

The square root of 1812643 is about 1346.3443096029. The cubic root of 1812643 is about 121.9281804292.

The spelling of 1812643 in words is "one million, eight hundred twelve thousand, six hundred forty-three".