309440436 has 48 divisors (see below), whose sum is σ = 764080128. Its totient is φ = 97266400.

The previous prime is 309440431. The next prime is 309440449. The reversal of 309440436 is 634044903.

309440436 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 309440397 and 309440406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (309440431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11701 + ... + 27491.

It is an arithmetic number, because the mean of its divisors is an integer number (15918336).

Almost surely, 2^309440436 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 309440436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (382040064).

309440436 is an abundant number, since it is smaller than the sum of its proper divisors (454639692).

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

309440436 is a wasteful number, since it uses less digits than its factorization.

309440436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15892 (or 15890 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 33.

The square root of 309440436 is about 17590.9191345990. The cubic root of 309440436 is about 676.3824878140.

The spelling of 309440436 in words is "three hundred nine million, four hundred forty thousand, four hundred thirty-six".