6720309 has 12 divisors (see below), whose sum is σ = 9867052. Its totient is φ = 4406400.

The previous prime is 6720299. The next prime is 6720323. The reversal of 6720309 is 9030276.

It can be written as a sum of positive squares in 2 ways, for example, as 815409 + 5904900 = 903^2 + 2430^2 .

It is not a de Polignac number, because 6720309 - 2¹⁶ = 6654773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6720409) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5572 + ... + 6669.

Almost surely, 2^6720309 is an apocalyptic number.

It is an amenable number.

6720309 is a deficient number, since it is larger than the sum of its proper divisors (3146743).

6720309 is a wasteful number, since it uses less digits than its factorization.

6720309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12308 (or 12305 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 27.

The square root of 6720309 is about 2592.3558783470. The cubic root of 6720309 is about 188.7106515640.

The spelling of 6720309 in words is "six million, seven hundred twenty thousand, three hundred nine".