42865909 has 2 divisors, whose sum is σ = 42865910. Its totient is φ = 42865908.

The previous prime is 42865873. The next prime is 42865913. The reversal of 42865909 is 90956824.

42865909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42380100 + 485809 = 6510^2 + 697^2 .

It is a cyclic number.

It is not a de Polignac number, because 42865909 - 2¹¹ = 42863861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42865409) by changing a digit.

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 as a sum of consecutive naturals, namely, 21432954 + 21432955.

It is an arithmetic number, because the mean of its divisors is an integer number (21432955).

Almost surely, 2^42865909 is an apocalyptic number.

It is an amenable number.

42865909 is a deficient number, since it is larger than the sum of its proper divisors (1).

42865909 is an equidigital number, since it uses as much as digits as its factorization.

42865909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 43.

The square root of 42865909 is about 6547.2061980665. The cubic root of 42865909 is about 349.9752608364.

The spelling of 42865909 in words is "forty-two million, eight hundred sixty-five thousand, nine hundred nine".