1812189 has 4 divisors (see below), whose sum is σ = 2416256. Its totient is φ = 1208124.

The previous prime is 1812157. The next prime is 1812199. The reversal of 1812189 is 9812181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9812181 = 3 ⋅3270727.

It is not a de Polignac number, because 1812189 - 2⁵ = 1812157 is a prime.

It is a D-number.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1812199) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 302029 + ... + 302034.

It is an arithmetic number, because the mean of its divisors is an integer number (604064).

2^1812189 is an apocalyptic number.

It is an amenable number.

1812189 is a deficient number, since it is larger than the sum of its proper divisors (604067).

1812189 is an equidigital number, since it uses as much as digits as its factorization.

1812189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 604066.

The product of its digits is 1152, while the sum is 30.

The square root of 1812189 is about 1346.1756943282. The cubic root of 1812189 is about 121.9180000800.

The spelling of 1812189 in words is "one million, eight hundred twelve thousand, one hundred eighty-nine".