1821806 has 16 divisors (see below), whose sum is σ = 3208416. Its totient is φ = 759456.

The previous prime is 1821791. The next prime is 1821821. The reversal of 1821806 is 6081281.

It is an interprime number because it is at equal distance from previous prime (1821791) and next prime (1821821).

It is a Curzon 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, 1241 + ... + 2276.

It is an arithmetic number, because the mean of its divisors is an integer number (200526).

2^1821806 is an apocalyptic number.

1821806 is a deficient number, since it is larger than the sum of its proper divisors (1386610).

1821806 is a wasteful number, since it uses less digits than its factorization.

1821806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3563.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 1821806 is about 1349.7429384887. The cubic root of 1821806 is about 122.1332862036.

The spelling of 1821806 in words is "one million, eight hundred twenty-one thousand, eight hundred six".