309072 has 40 divisors (see below), whose sum is σ = 821376. Its totient is φ = 100096.

The previous prime is 309059. The next prime is 309079. The reversal of 309072 is 270903.

309072 is nontrivially palindromic in base 13.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309079) 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, 2188 + ... + 2324.

2³⁰⁹⁰⁷² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 309072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (410688).

309072 is an abundant number, since it is smaller than the sum of its proper divisors (512304).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

309072 is a wasteful number, since it uses less digits than its factorization.

309072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 189 counting only the distinct ones).

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

The square root of 309072 is about 555.9424430640. The cubic root of 309072 is about 67.6113935723.

Adding to 309072 its reverse (270903), we get a palindrome (579975).

The spelling of 309072 in words is "three hundred nine thousand, seventy-two".