1803021 has 12 divisors (see below), whose sum is σ = 2642976. Its totient is φ = 1092520.

The previous prime is 1803001. The next prime is 1803023. The reversal of 1803021 is 1203081.

It is a happy number.

It is not a de Polignac number, because 1803021 - 2⁵ = 1802989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1803023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2121 + ... + 2846.

It is an arithmetic number, because the mean of its divisors is an integer number (220248).

2^1803021 is an apocalyptic number.

1803021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1803021 is a deficient number, since it is larger than the sum of its proper divisors (839955).

1803021 is a wasteful number, since it uses less digits than its factorization.

1803021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4992 (or 4981 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1803021 is about 1342.7661747304. The cubic root of 1803021 is about 121.7120549573.

The spelling of 1803021 in words is "one million, eight hundred three thousand, twenty-one".