721013 has 2 divisors, whose sum is σ = 721014. Its totient is φ = 721012.

The previous prime is 721003. The next prime is 721037. The reversal of 721013 is 310127.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 702244 + 18769 = 838^2 + 137^2 .

It is an emirp because it is prime and its reverse (310127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721013 - 2⁴ = 720997 is a prime.

It is a Chen prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721013.

It is not a weakly prime, because it can be changed into another prime (721003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360506 + 360507.

It is an arithmetic number, because the mean of its divisors is an integer number (360507).

2⁷²¹⁰¹³ is an apocalyptic number.

It is an amenable number.

721013 is a deficient number, since it is larger than the sum of its proper divisors (1).

721013 is an equidigital number, since it uses as much as digits as its factorization.

721013 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 14.

The square root of 721013 is about 849.1248435890. The cubic root of 721013 is about 89.6701091502.

The spelling of 721013 in words is "seven hundred twenty-one thousand, thirteen".