1816889 has 4 divisors (see below), whose sum is σ = 1834980. Its totient is φ = 1798800.

The previous prime is 1816861. The next prime is 1816901. The reversal of 1816889 is 9886181.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9886181 = 2803 ⋅3527.

It can be written as a sum of positive squares in 2 ways, for example, as 1605289 + 211600 = 1267^2 + 460^2 .

It is a cyclic number.

It is not a de Polignac number, because 1816889 - 2¹² = 1812793 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1816849) 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, 8894 + ... + 9095.

It is an arithmetic number, because the mean of its divisors is an integer number (458745).

2^1816889 is an apocalyptic number.

It is an amenable number.

1816889 is a deficient number, since it is larger than the sum of its proper divisors (18091).

1816889 is a wasteful number, since it uses less digits than its factorization.

1816889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18090.

The product of its digits is 27648, while the sum is 41.

The square root of 1816889 is about 1347.9202498664. The cubic root of 1816889 is about 122.0233091717.

The spelling of 1816889 in words is "one million, eight hundred sixteen thousand, eight hundred eighty-nine".