1805220 has 48 divisors (see below), whose sum is σ = 5617920. Its totient is φ = 481248.

The previous prime is 1805203. The next prime is 1805227. The reversal of 1805220 is 225081.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1805193 and 1805202.

It is not an unprimeable number, because it can be changed into a prime (1805227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1132 + ... + 2211.

It is an arithmetic number, because the mean of its divisors is an integer number (117040).

2^1805220 is an apocalyptic number.

1805220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1805220 is an abundant number, since it is smaller than the sum of its proper divisors (3812700).

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

1805220 is a wasteful number, since it uses less digits than its factorization.

1805220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3361 (or 3353 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 1805220 is about 1343.5847572818. The cubic root of 1805220 is about 121.7615156632.

It can be divided in two parts, 1805 and 220, that added together give a square (2025 = 45²).

The spelling of 1805220 in words is "one million, eight hundred five thousand, two hundred twenty".