1865989 has 4 divisors (see below), whose sum is σ = 1885324. Its totient is φ = 1846656.

The previous prime is 1865987. The next prime is 1865999. The reversal of 1865989 is 9895681.

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

It can be written as a sum of positive squares in 2 ways, for example, as 504100 + 1361889 = 710^2 + 1167^2 .

It is a cyclic number.

It is not a de Polignac number, because 1865989 - 2¹ = 1865987 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1865987) 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, 9522 + ... + 9715.

It is an arithmetic number, because the mean of its divisors is an integer number (471331).

2^1865989 is an apocalyptic number.

It is an amenable number.

1865989 is a deficient number, since it is larger than the sum of its proper divisors (19335).

1865989 is an equidigital number, since it uses as much as digits as its factorization.

1865989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19334.

The product of its digits is 155520, while the sum is 46.

The square root of 1865989 is about 1366.0120790096. The cubic root of 1865989 is about 123.1127483150.

The spelling of 1865989 in words is "one million, eight hundred sixty-five thousand, nine hundred eighty-nine".