818181818181809 has 8 divisors (see below), whose sum is σ = 838712371115520. Its totient is φ = 797719586556816.

The previous prime is 818181818181797. The next prime is 818181818181811. The reversal of 818181818181809 is 908181818181818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 818181818181809 - 2²⁴ = 818181801404593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (818181818181839) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17080302929 + ... + 17080350830.

It is an arithmetic number, because the mean of its divisors is an integer number (104839046389440).

Almost surely, 2^{818181818181809} is an apocalyptic number.

It is an amenable number.

818181818181809 is a deficient number, since it is larger than the sum of its proper divisors (20530552933711).

818181818181809 is a wasteful number, since it uses less digits than its factorization.

818181818181809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34160654359.

The product of its (nonzero) digits is 18874368, while the sum is 71.

Subtracting 818181818181809 from its reverse (908181818181818), we obtain a palindrome (90000000000009).

The spelling of 818181818181809 in words is "eight hundred eighteen trillion, one hundred eighty-one billion, eight hundred eighteen million, one hundred eighty-one thousand, eight hundred nine".