2021805 has 24 divisors (see below), whose sum is σ = 3538080. Its totient is φ = 1068000.

The previous prime is 2021801. The next prime is 2021807. The reversal of 2021805 is 5081202.

It is not a de Polignac number, because 2021805 - 2² = 2021801 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021801) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7930 + ... + 8180.

It is an arithmetic number, because the mean of its divisors is an integer number (147420).

2^2021805 is an apocalyptic number.

It is an amenable number.

2021805 is a deficient number, since it is larger than the sum of its proper divisors (1516275).

2021805 is a wasteful number, since it uses less digits than its factorization.

2021805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441 (or 438 counting only the distinct ones).

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

The square root of 2021805 is about 1421.9018953500. The cubic root of 2021805 is about 126.4483273050.

The spelling of 2021805 in words is "two million, twenty-one thousand, eight hundred five".