720309 has 8 divisors (see below), whose sum is σ = 1011040. Its totient is φ = 454896.

The previous prime is 720301. The next prime is 720311. The reversal of 720309 is 903027.

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

It is not a de Polignac number, because 720309 - 2³ = 720301 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (720301) 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, 6262 + ... + 6375.

It is an arithmetic number, because the mean of its divisors is an integer number (126380).

2⁷²⁰³⁰⁹ is an apocalyptic number.

It is an amenable number.

720309 is a deficient number, since it is larger than the sum of its proper divisors (290731).

720309 is a wasteful number, since it uses less digits than its factorization.

720309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12659.

The product of its (nonzero) digits is 378, while the sum is 21.

The square root of 720309 is about 848.7101978885. The cubic root of 720309 is about 89.6409148943.

The spelling of 720309 in words is "seven hundred twenty thousand, three hundred nine".