221820182209 has 8 divisors (see below), whose sum is σ = 224881381512. Its totient is φ = 218759592960.

The previous prime is 221820182203. The next prime is 221820182231. The reversal of 221820182209 is 902281028122.

221820182209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8586802225 + 213233379984 = 92665^2 + 461772^2 .

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 221820182209 - 2⁷ = 221820182081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221820182203) 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 7 ways as a sum of consecutive naturals, for example, 605529 + ... + 900169.

It is an arithmetic number, because the mean of its divisors is an integer number (28110172689).

Almost surely, 2^221820182209 is an apocalyptic number.

It is an amenable number.

221820182209 is a deficient number, since it is larger than the sum of its proper divisors (3061199303).

221820182209 is a wasteful number, since it uses less digits than its factorization.

221820182209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305027.

The product of its (nonzero) digits is 18432, while the sum is 37.

The spelling of 221820182209 in words is "two hundred twenty-one billion, eight hundred twenty million, one hundred eighty-two thousand, two hundred nine".