1800005 has 8 divisors (see below), whose sum is σ = 2174712. Its totient is φ = 1430208.

The previous prime is 1799999. The next prime is 1800017. The reversal of 1800005 is 5000081.

It can be written as a sum of positive squares in 4 ways, for example, as 20449 + 1779556 = 143^2 + 1334^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1800005 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 362 + ... + 1931.

It is an arithmetic number, because the mean of its divisors is an integer number (271839).

2^1800005 is an apocalyptic number.

It is an amenable number.

1800005 is a deficient number, since it is larger than the sum of its proper divisors (374707).

1800005 is a wasteful number, since it uses less digits than its factorization.

1800005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2455.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 1800005 is about 1341.6426498886. The cubic root of 1800005 is about 121.6441525447.

Adding to 1800005 its reverse (5000081), we get a palindrome (6800086).

The spelling of 1800005 in words is "one million, eight hundred thousand, five".