42390109 has 2 divisors, whose sum is σ = 42390110. Its totient is φ = 42390108.

The previous prime is 42390107. The next prime is 42390119. The reversal of 42390109 is 90109324.

It is a happy number.

42390109 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36264484 + 6125625 = 6022^2 + 2475^2 .

It is a cyclic number.

It is not a de Polignac number, because 42390109 - 2¹ = 42390107 is a prime.

Together with 42390107, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42390107) 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, 21195054 + 21195055.

It is an arithmetic number, because the mean of its divisors is an integer number (21195055).

Almost surely, 2^42390109 is an apocalyptic number.

It is an amenable number.

42390109 is a deficient number, since it is larger than the sum of its proper divisors (1).

42390109 is an equidigital number, since it uses as much as digits as its factorization.

42390109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 42390109 is about 6510.7686950160. The cubic root of 42390109 is about 348.6755632213.

The spelling of 42390109 in words is "forty-two million, three hundred ninety thousand, one hundred nine".