309408 has 48 divisors (see below), whose sum is σ = 889056. Its totient is φ = 93440.

The previous prime is 309403. The next prime is 309433. The reversal of 309408 is 804903.

309408 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (309403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 910 + ... + 1202.

It is an arithmetic number, because the mean of its divisors is an integer number (18522).

2³⁰⁹⁴⁰⁸ 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 309408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (444528).

309408 is an abundant number, since it is smaller than the sum of its proper divisors (579648).

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

309408 is a wasteful number, since it uses less digits than its factorization.

309408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 317 (or 309 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 309408 is about 556.2445505351. The cubic root of 309408 is about 67.6358853854.

It can be divided in two parts, 309 and 408, that added together give a palindrome (717).

The spelling of 309408 in words is "three hundred nine thousand, four hundred eight".