17218508805 has 12 divisors (see below), whose sum is σ = 29845415340. Its totient is φ = 9183204672.

The previous prime is 17218508773. The next prime is 17218508809. The reversal of 17218508805 is 50880581271.

It can be written as a sum of positive squares in 2 ways, for example, as 7754915844 + 9463592961 = 88062^2 + 97281^2 .

It is not a de Polignac number, because 17218508805 - 2⁵ = 17218508773 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 382633529 = 17218508805 / (1 + 7 + 2 + 1 + 8 + 5 + 0 + 8 + 8 + 0 + 5).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17218508809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 191316720 + ... + 191316809.

It is an arithmetic number, because the mean of its divisors is an integer number (2487117945).

Almost surely, 2^17218508805 is an apocalyptic number.

17218508805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

17218508805 is a deficient number, since it is larger than the sum of its proper divisors (12626906535).

17218508805 is a wasteful number, since it uses less digits than its factorization.

17218508805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 382633540 (or 382633537 counting only the distinct ones).

The product of its (nonzero) digits is 179200, while the sum is 45.

The spelling of 17218508805 in words is "seventeen billion, two hundred eighteen million, five hundred eight thousand, eight hundred five".