309439768 has 64 divisors (see below), whose sum is σ = 663505920. Its totient is φ = 134006400.

The previous prime is 309439759. The next prime is 309439771. The reversal of 309439768 is 867934903.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 181930 + ... + 183622.

It is an arithmetic number, because the mean of its divisors is an integer number (10367280).

Almost surely, 2^309439768 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 309439768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (331752960).

309439768 is an abundant number, since it is smaller than the sum of its proper divisors (354066152).

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

309439768 is a wasteful number, since it uses less digits than its factorization.

309439768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1808 (or 1804 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 49.

The square root of 309439768 is about 17590.9001475195. The cubic root of 309439768 is about 676.3820011034.

The spelling of 309439768 in words is "three hundred nine million, four hundred thirty-nine thousand, seven hundred sixty-eight".