6721603 has 4 divisors (see below), whose sum is σ = 7681840. Its totient is φ = 5761368.

The previous prime is 6721577. The next prime is 6721609. The reversal of 6721603 is 3061276.

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

It is a cyclic number.

It is not a de Polignac number, because 6721603 - 2⁵ = 6721571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6721609) 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, 480108 + ... + 480121.

It is an arithmetic number, because the mean of its divisors is an integer number (1920460).

Almost surely, 2^6721603 is an apocalyptic number.

6721603 is a deficient number, since it is larger than the sum of its proper divisors (960237).

6721603 is an equidigital number, since it uses as much as digits as its factorization.

6721603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 960236.

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 6721603 is about 2592.6054462644. The cubic root of 6721603 is about 188.7227629075.

Adding to 6721603 its reverse (3061276), we get a palindrome (9782879).

The spelling of 6721603 in words is "six million, seven hundred twenty-one thousand, six hundred three".