721723 has 8 divisors (see below), whose sum is σ = 766080. Its totient is φ = 678720.

The previous prime is 721709. The next prime is 721733. The reversal of 721723 is 327127.

721723 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-721723 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721694 and 721703.

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 7 ways as a sum of consecutive naturals, for example, 886 + ... + 1492.

It is an arithmetic number, because the mean of its divisors is an integer number (95760).

2⁷²¹⁷²³ is an apocalyptic number.

721723 is a deficient number, since it is larger than the sum of its proper divisors (44357).

721723 is a wasteful number, since it uses less digits than its factorization.

721723 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 677.

The product of its digits is 588, while the sum is 22.

The square root of 721723 is about 849.5428182264. The cubic root of 721723 is about 89.6995329798.

It can be divided in two parts, 721 and 723, that added together give a square (1444 = 38²).

The spelling of 721723 in words is "seven hundred twenty-one thousand, seven hundred twenty-three", and thus it is an iban number.