1820445 has 48 divisors (see below), whose sum is σ = 3447360. Its totient is φ = 816640.

The previous prime is 1820431. The next prime is 1820449. The reversal of 1820445 is 5440281.

It is not a de Polignac number, because 1820445 - 2⁹ = 1819933 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820449) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 30826 + ... + 30884.

It is an arithmetic number, because the mean of its divisors is an integer number (71820).

2^1820445 is an apocalyptic number.

1820445 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1820445 is a deficient number, since it is larger than the sum of its proper divisors (1626915).

1820445 is a wasteful number, since it uses less digits than its factorization.

1820445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 1820445 is about 1349.2386742159. The cubic root of 1820445 is about 122.1028649600.

The spelling of 1820445 in words is "one million, eight hundred twenty thousand, four hundred forty-five".