2021403 has 4 divisors (see below), whose sum is σ = 2695208. Its totient is φ = 1347600.

The previous prime is 2021381. The next prime is 2021431. The reversal of 2021403 is 3041202.

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

It is not a de Polignac number, because 2021403 - 2⁶ = 2021339 is a prime.

It is a D-number.

It is a Duffinian number.

2021403 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2021003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 336898 + ... + 336903.

It is an arithmetic number, because the mean of its divisors is an integer number (673802).

2^2021403 is an apocalyptic number.

2021403 is a deficient number, since it is larger than the sum of its proper divisors (673805).

2021403 is an equidigital number, since it uses as much as digits as its factorization.

2021403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 673804.

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 2021403 is about 1421.7605283591. The cubic root of 2021403 is about 126.4399460817.

Adding to 2021403 its reverse (3041202), we get a palindrome (5062605).

The spelling of 2021403 in words is "two million, twenty-one thousand, four hundred three".