721003 has 2 divisors, whose sum is σ = 721004. Its totient is φ = 721002.

The previous prime is 720997. The next prime is 721013. The reversal of 721003 is 300127.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 721003 - 2⁵ = 720971 is a prime.

It is not a weakly prime, because it can be changed into another prime (721013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360501 + 360502.

It is an arithmetic number, because the mean of its divisors is an integer number (360502).

2⁷²¹⁰⁰³ is an apocalyptic number.

721003 is a deficient number, since it is larger than the sum of its proper divisors (1).

721003 is an equidigital number, since it uses as much as digits as its factorization.

721003 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42, while the sum is 13.

The square root of 721003 is about 849.1189551529. The cubic root of 721003 is about 89.6696945921.

The spelling of 721003 in words is "seven hundred twenty-one thousand, three", and thus it is an iban number.