135666423605 has 4 divisors (see below), whose sum is σ = 162799708332. Its totient is φ = 108533138880.

The previous prime is 135666423553. The next prime is 135666423643. The reversal of 135666423605 is 506324666531.

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 89133893809 + 46532529796 = 298553^2 + 215714^2 .

It is not a de Polignac number, because 135666423605 - 2¹⁰ = 135666422581 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 135666423605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13566642356 + ... + 13566642365.

It is an arithmetic number, because the mean of its divisors is an integer number (40699927083).

Almost surely, 2^135666423605 is an apocalyptic number.

It is an amenable number.

135666423605 is a deficient number, since it is larger than the sum of its proper divisors (27133284727).

135666423605 is an equidigital number, since it uses as much as digits as its factorization.

135666423605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27133284726.

The product of its (nonzero) digits is 2332800, while the sum is 47.

The spelling of 135666423605 in words is "one hundred thirty-five billion, six hundred sixty-six million, four hundred twenty-three thousand, six hundred five".