1808239 has 4 divisors (see below), whose sum is σ = 1914624. Its totient is φ = 1701856.

The previous prime is 1808207. The next prime is 1808243. The reversal of 1808239 is 9328081.

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

It is a cyclic number.

It is not a de Polignac number, because 1808239 - 2⁵ = 1808207 is a prime.

It is a super-2 number, since 2×1808239² = 6539456562242, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1808239.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1808269) 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, 53167 + ... + 53200.

It is an arithmetic number, because the mean of its divisors is an integer number (478656).

2^1808239 is an apocalyptic number.

1808239 is a deficient number, since it is larger than the sum of its proper divisors (106385).

1808239 is a wasteful number, since it uses less digits than its factorization.

1808239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106384.

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 1808239 is about 1344.7077749459. The cubic root of 1808239 is about 121.8293547236.

The spelling of 1808239 in words is "one million, eight hundred eight thousand, two hundred thirty-nine".