108209905 has 4 divisors (see below), whose sum is σ = 129851892. Its totient is φ = 86567920.

The previous prime is 108209903. The next prime is 108209923. The reversal of 108209905 is 509902801.

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 62078641 + 46131264 = 7879^2 + 6792^2 .

It is not a de Polignac number, because 108209905 - 2¹ = 108209903 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (108209903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10820986 + ... + 10820995.

It is an arithmetic number, because the mean of its divisors is an integer number (32462973).

Almost surely, 2^108209905 is an apocalyptic number.

It is an amenable number.

108209905 is a deficient number, since it is larger than the sum of its proper divisors (21641987).

108209905 is an equidigital number, since it uses as much as digits as its factorization.

108209905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21641986.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 108209905 is about 10402.3990021533. The cubic root of 108209905 is about 476.5286376119.

The spelling of 108209905 in words is "one hundred eight million, two hundred nine thousand, nine hundred five".