218081949209 has 4 divisors (see below), whose sum is σ = 218089798416. Its totient is φ = 218074100004.

The previous prime is 218081949203. The next prime is 218081949229. The reversal of 218081949209 is 902949180812.

It is a happy number.

218081949209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 218081949209 - 2²⁰ = 218080900633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218081949203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3882779 + ... + 3938544.

It is an arithmetic number, because the mean of its divisors is an integer number (54522449604).

Almost surely, 2^218081949209 is an apocalyptic number.

It is an amenable number.

218081949209 is a deficient number, since it is larger than the sum of its proper divisors (7849207).

218081949209 is an equidigital number, since it uses as much as digits as its factorization.

218081949209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7849206.

The product of its (nonzero) digits is 746496, while the sum is 53.

The spelling of 218081949209 in words is "two hundred eighteen billion, eighty-one million, nine hundred forty-nine thousand, two hundred nine".