1805420 has 12 divisors (see below), whose sum is σ = 3791424. Its totient is φ = 722160.

The previous prime is 1805413. The next prime is 1805473. The reversal of 1805420 is 245081.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 90271 = 1805420 / (1 + 8 + 0 + 5 + 4 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 1805392 and 1805401.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 45116 + ... + 45155.

It is an arithmetic number, because the mean of its divisors is an integer number (315952).

2^1805420 is an apocalyptic number.

1805420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1805420 is an abundant number, since it is smaller than the sum of its proper divisors (1986004).

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

1805420 is a wasteful number, since it uses less digits than its factorization.

1805420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90280 (or 90278 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 1805420 is about 1343.6591829776. The cubic root of 1805420 is about 121.7660121427.

The spelling of 1805420 in words is "one million, eight hundred five thousand, four hundred twenty".