309123072 has 144 divisors (see below), whose sum is σ = 923307840. Its totient is φ = 99532800.

The previous prime is 309123071. The next prime is 309123091. The reversal of 309123072 is 270321903.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309123071) 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, 571122 + ... + 571662.

It is an arithmetic number, because the mean of its divisors is an integer number (6411860).

Almost surely, 2^309123072 is an apocalyptic number.

309123072 is a gapful number since it is divisible by the number (32) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 309123072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (461653920).

309123072 is an abundant number, since it is smaller than the sum of its proper divisors (614184768).

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

309123072 is a wasteful number, since it uses less digits than its factorization.

309123072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 600 (or 577 counting only the distinct ones).

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

The square root of 309123072 is about 17581.8961434767. The cubic root of 309123072 is about 676.1511747145.

Adding to 309123072 its reverse (270321903), we get a palindrome (579444975).

The spelling of 309123072 in words is "three hundred nine million, one hundred twenty-three thousand, seventy-two".