438728309 has 4 divisors (see below), whose sum is σ = 439227180. Its totient is φ = 438229440.

The previous prime is 438728293. The next prime is 438728347. The reversal of 438728309 is 903827834.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 153016900 + 285711409 = 12370^2 + 16903^2 .

It is a cyclic number.

It is not a de Polignac number, because 438728309 - 2⁴ = 438728293 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 438728309.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (438728359) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 248114 + ... + 249875.

It is an arithmetic number, because the mean of its divisors is an integer number (109806795).

Almost surely, 2^438728309 is an apocalyptic number.

It is an amenable number.

438728309 is a deficient number, since it is larger than the sum of its proper divisors (498871).

438728309 is an equidigital number, since it uses as much as digits as its factorization.

438728309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498870.

The product of its (nonzero) digits is 290304, while the sum is 44.

The square root of 438728309 is about 20945.8422843294. The cubic root of 438728309 is about 759.8570304704.

The spelling of 438728309 in words is "four hundred thirty-eight million, seven hundred twenty-eight thousand, three hundred nine".