2021806 has 4 divisors (see below), whose sum is σ = 3032712. Its totient is φ = 1010902.

The previous prime is 2021801. The next prime is 2021807. The reversal of 2021806 is 6081202.

It is a happy number.

It is a semiprime because it is the product of two primes.

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 as a sum of consecutive naturals, namely, 505450 + ... + 505453.

It is an arithmetic number, because the mean of its divisors is an integer number (758178).

2^2021806 is an apocalyptic number.

2021806 is a deficient number, since it is larger than the sum of its proper divisors (1010906).

2021806 is a wasteful number, since it uses less digits than its factorization.

2021806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010905.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 2021806 is about 1421.9022469917. The cubic root of 2021806 is about 126.4483481524.

The spelling of 2021806 in words is "two million, twenty-one thousand, eight hundred six".