721713 has 4 divisors (see below), whose sum is σ = 962288. Its totient is φ = 481140.

The previous prime is 721709. The next prime is 721733. The reversal of 721713 is 317127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 721713 - 2² = 721709 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 721713.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 721713.

It is not an unprimeable number, because it can be changed into a prime (721703) 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, 120283 + ... + 120288.

It is an arithmetic number, because the mean of its divisors is an integer number (240572).

2⁷²¹⁷¹³ is an apocalyptic number.

It is an amenable number.

721713 is a deficient number, since it is larger than the sum of its proper divisors (240575).

721713 is a wasteful number, since it uses less digits than its factorization.

721713 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240574.

The product of its digits is 294, while the sum is 21.

The square root of 721713 is about 849.5369326874. The cubic root of 721713 is about 89.6991186937.

The spelling of 721713 in words is "seven hundred twenty-one thousand, seven hundred thirteen".