42686666809 has 2 divisors, whose sum is σ = 42686666810. Its totient is φ = 42686666808.

The previous prime is 42686666807. The next prime is 42686666839. The reversal of 42686666809 is 90866668624.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21892161600 + 20794505209 = 147960^2 + 144203^2 .

It is a cyclic number.

It is not a de Polignac number, because 42686666809 - 2¹ = 42686666807 is a prime.

It is a super-3 number, since 3×42686666809³ (a number of 33 digits) contains 333 as substring.

Together with 42686666807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (42686666801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21343333404 + 21343333405.

It is an arithmetic number, because the mean of its divisors is an integer number (21343333405).

Almost surely, 2^42686666809 is an apocalyptic number.

It is an amenable number.

42686666809 is a deficient number, since it is larger than the sum of its proper divisors (1).

42686666809 is an equidigital number, since it uses as much as digits as its factorization.

42686666809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35831808, while the sum is 61.

The spelling of 42686666809 in words is "forty-two billion, six hundred eighty-six million, six hundred sixty-six thousand, eight hundred nine".