724809 has 4 divisors (see below), whose sum is σ = 966416. Its totient is φ = 483204.

The previous prime is 724807. The next prime is 724813. The reversal of 724809 is 908427.

724809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 724809 - 2¹ = 724807 is a prime.

It is a D-number.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 724809.

It is not an unprimeable number, because it can be changed into a prime (724807) 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, 120799 + ... + 120804.

It is an arithmetic number, because the mean of its divisors is an integer number (241604).

2⁷²⁴⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

724809 is a deficient number, since it is larger than the sum of its proper divisors (241607).

724809 is a wasteful number, since it uses less digits than its factorization.

724809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241606.

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 724809 is about 851.3571518464. The cubic root of 724809 is about 89.8271992978.

The spelling of 724809 in words is "seven hundred twenty-four thousand, eight hundred nine".