1803906 has 36 divisors (see below), whose sum is σ = 4239378. Its totient is φ = 554112.

The previous prime is 1803889. The next prime is 1803947. The reversal of 1803906 is 6093081.

It can be written as a sum of positive squares in 3 ways, for example, as 1010025 + 793881 = 1005^2 + 891^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1803906.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 2746 + ... + 3338.

2^1803906 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1803906, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2119689).

1803906 is an abundant number, since it is smaller than the sum of its proper divisors (2435472).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1803906 is a wasteful number, since it uses less digits than its factorization.

1803906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627 (or 611 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 1803906 is about 1343.0956779024. The cubic root of 1803906 is about 121.7319655314.

Adding to 1803906 its reverse (6093081), we get a palindrome (7896987).

The spelling of 1803906 in words is "one million, eight hundred three thousand, nine hundred six".