1805490 has 48 divisors (see below), whose sum is σ = 4874688. Its totient is φ = 480816.

The previous prime is 1805483. The next prime is 1805491. The reversal of 1805490 is 945081.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1805491) 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 23 ways as a sum of consecutive naturals, for example, 2059 + ... + 2801.

It is an arithmetic number, because the mean of its divisors is an integer number (101556).

2^1805490 is an apocalyptic number.

1805490 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1805490, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2437344).

1805490 is an abundant number, since it is smaller than the sum of its proper divisors (3069198).

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

1805490 is an equidigital number, since it uses as much as digits as its factorization.

1805490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765 (or 753 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 1805490 is about 1343.6852309972. The cubic root of 1805490 is about 121.7675858320.

Subtracting from 1805490 its product of nonzero digits (1440), we obtain a triangular number (1804050 = T₁₈₉₉).

The spelling of 1805490 in words is "one million, eight hundred five thousand, four hundred ninety".