2021606 has 16 divisors (see below), whose sum is σ = 3299616. Its totient is φ = 925056.

The previous prime is 2021599. The next prime is 2021609. The reversal of 2021606 is 6061202.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021609) 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 7 ways as a sum of consecutive naturals, for example, 455 + ... + 2061.

It is an arithmetic number, because the mean of its divisors is an integer number (206226).

2^2021606 is an apocalyptic number.

2021606 is a deficient number, since it is larger than the sum of its proper divisors (1278010).

2021606 is a wasteful number, since it uses less digits than its factorization.

2021606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1663.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 2021606 is about 1421.8319169297. The cubic root of 2021606 is about 126.4441785299. Note that the first 3 decimals are identical.

Adding to 2021606 its reverse (6061202), we get a palindrome (8082808).

The spelling of 2021606 in words is "two million, twenty-one thousand, six hundred six".