17918775409909 has 4 divisors (see below), whose sum is σ = 19547754992640. Its totient is φ = 16289795827180.

The previous prime is 17918775409889. The next prime is 17918775409937. The reversal of 17918775409909 is 90990457781971.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-17918775409909 is a prime.

It is a Smith number, since the sum of its digits (76) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17918775409979) 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, 814489791349 + ... + 814489791370.

It is an arithmetic number, because the mean of its divisors is an integer number (4886938748160).

Almost surely, 2^{17918775409909} is an apocalyptic number.

It is an amenable number.

17918775409909 is a deficient number, since it is larger than the sum of its proper divisors (1628979582731).

17918775409909 is a wasteful number, since it uses less digits than its factorization.

17918775409909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1628979582730.

The product of its (nonzero) digits is 360067680, while the sum is 76.

The spelling of 17918775409909 in words is "seventeen trillion, nine hundred eighteen billion, seven hundred seventy-five million, four hundred nine thousand, nine hundred nine".