1866789 has 12 divisors (see below), whose sum is σ = 2783872. Its totient is φ = 1204200.

The previous prime is 1866779. The next prime is 1866827. The reversal of 1866789 is 9876681.

It is a happy number.

1866789 is nontrivially palindromic in base 11.

It is not a de Polignac number, because 1866789 - 2⁵ = 1866757 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1866779) 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 11 ways as a sum of consecutive naturals, for example, 3067 + ... + 3624.

2^1866789 is an apocalyptic number.

It is an amenable number.

1866789 is a deficient number, since it is larger than the sum of its proper divisors (917083).

1866789 is a wasteful number, since it uses less digits than its factorization.

1866789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6728 (or 6725 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 1866789 is about 1366.3048708103. The cubic root of 1866789 is about 123.1303397239.

The spelling of 1866789 in words is "one million, eight hundred sixty-six thousand, seven hundred eighty-nine".