309840738 has 16 divisors (see below), whose sum is σ = 636430080. Its totient is φ = 100488816.

The previous prime is 309840737. The next prime is 309840749. The reversal of 309840738 is 837048903.

309840738 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 309840738.

It is not an unprimeable number, because it can be changed into a prime (309840737) 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, 697618 + ... + 698061.

It is an arithmetic number, because the mean of its divisors is an integer number (39776880).

Almost surely, 2^309840738 is an apocalyptic number.

309840738 is an abundant number, since it is smaller than the sum of its proper divisors (326589342).

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

309840738 is a wasteful number, since it uses less digits than its factorization.

309840738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1395721.

The product of its (nonzero) digits is 145152, while the sum is 42.

The square root of 309840738 is about 17602.2935437403. The cubic root of 309840738 is about 676.6740254430.

The spelling of 309840738 in words is "three hundred nine million, eight hundred forty thousand, seven hundred thirty-eight".