2021603 has 4 divisors (see below), whose sum is σ = 2086848. Its totient is φ = 1956360.

The previous prime is 2021599. The next prime is 2021609. The reversal of 2021603 is 3061202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3061202 = 2 ⋅1530601.

It is a cyclic number.

It is not a de Polignac number, because 2021603 - 2² = 2021599 is a prime.

It is a Duffinian 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 3 ways as a sum of consecutive naturals, for example, 32576 + ... + 32637.

It is an arithmetic number, because the mean of its divisors is an integer number (521712).

2^2021603 is an apocalyptic number.

2021603 is a deficient number, since it is larger than the sum of its proper divisors (65245).

2021603 is an equidigital number, since it uses as much as digits as its factorization.

2021603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65244.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 2021603 is about 1421.8308619523. The cubic root of 2021603 is about 126.4441159834. Note that the first 3 decimals are identical.

Adding to 2021603 its reverse (3061202), we get a palindrome (5082805).

The spelling of 2021603 in words is "two million, twenty-one thousand, six hundred three".