438685109 has 2 divisors, whose sum is σ = 438685110. Its totient is φ = 438685108.

The previous prime is 438685069. The next prime is 438685111. The reversal of 438685109 is 901586834.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 240157009 + 198528100 = 15497^2 + 14090^2 .

It is a cyclic number.

It is not a de Polignac number, because 438685109 - 2¹² = 438681013 is a prime.

Together with 438685111, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 438685109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (438685139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 219342554 + 219342555.

It is an arithmetic number, because the mean of its divisors is an integer number (219342555).

Almost surely, 2^438685109 is an apocalyptic number.

It is an amenable number.

438685109 is a deficient number, since it is larger than the sum of its proper divisors (1).

438685109 is an equidigital number, since it uses as much as digits as its factorization.

438685109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 207360, while the sum is 44.

The square root of 438685109 is about 20944.8110280327. The cubic root of 438685109 is about 759.8320895213.

The spelling of 438685109 in words is "four hundred thirty-eight million, six hundred eighty-five thousand, one hundred nine".