17818605905 has 4 divisors (see below), whose sum is σ = 21382327092. Its totient is φ = 14254884720.

The previous prime is 17818605901. The next prime is 17818605907. The reversal of 17818605905 is 50950681871.

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 12367441681 + 5451164224 = 111209^2 + 73832^2 .

It is not a de Polignac number, because 17818605905 - 2² = 17818605901 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (17818605901) 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 in 3 ways as a sum of consecutive naturals, for example, 1781860586 + ... + 1781860595.

It is an arithmetic number, because the mean of its divisors is an integer number (5345581773).

Almost surely, 2^17818605905 is an apocalyptic number.

It is an amenable number.

17818605905 is a deficient number, since it is larger than the sum of its proper divisors (3563721187).

17818605905 is an equidigital number, since it uses as much as digits as its factorization.

17818605905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3563721186.

The product of its (nonzero) digits is 604800, while the sum is 50.

The spelling of 17818605905 in words is "seventeen billion, eight hundred eighteen million, six hundred five thousand, nine hundred five".