1806989 has 4 divisors (see below), whose sum is σ = 1849056. Its totient is φ = 1764924.

The previous prime is 1806977. The next prime is 1807027. The reversal of 1806989 is 9896081.

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.

It is a cyclic number.

It is not a de Polignac number, because 1806989 - 2⁸ = 1806733 is a prime.

It is a super-2 number, since 2×1806989² = 6530418492242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1806089) 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, 20969 + ... + 21054.

It is an arithmetic number, because the mean of its divisors is an integer number (462264).

2^1806989 is an apocalyptic number.

It is an amenable number.

1806989 is a deficient number, since it is larger than the sum of its proper divisors (42067).

1806989 is an equidigital number, since it uses as much as digits as its factorization.

1806989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42066.

The product of its (nonzero) digits is 31104, while the sum is 41.

The square root of 1806989 is about 1344.2429095963. The cubic root of 1806989 is about 121.8012755081.

The spelling of 1806989 in words is "one million, eight hundred six thousand, nine hundred eighty-nine".