726409 has 4 divisors (see below), whose sum is σ = 758016. Its totient is φ = 694804.

The previous prime is 726391. The next prime is 726413. The reversal of 726409 is 904627.

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 a cyclic number.

It is not a de Polignac number, because 726409 - 2⁵ = 726377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (726419) 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, 15769 + ... + 15814.

It is an arithmetic number, because the mean of its divisors is an integer number (189504).

2⁷²⁶⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

726409 is a deficient number, since it is larger than the sum of its proper divisors (31607).

726409 is a wasteful number, since it uses less digits than its factorization.

726409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31606.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 726409 is about 852.2963099768. The cubic root of 726409 is about 89.8932479133.

The spelling of 726409 in words is "seven hundred twenty-six thousand, four hundred nine".