221111222202221 has 4 divisors (see below), whose sum is σ = 238119777756252. Its totient is φ = 204102666648192.

The previous prime is 221111222202191. The next prime is 221111222202257. The reversal of 221111222202221 is 122202222111122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 40969459746121 + 180141762456100 = 6400739^2 + 13421690^2 .

It is not a de Polignac number, because 221111222202221 - 2³⁴ = 221094042333037 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221111222222221) 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, 8504277776996 + ... + 8504277777021.

It is an arithmetic number, because the mean of its divisors is an integer number (59529944439063).

Almost surely, 2^{221111222202221} is an apocalyptic number.

It is an amenable number.

221111222202221 is a deficient number, since it is larger than the sum of its proper divisors (17008555554031).

221111222202221 is a wasteful number, since it uses less digits than its factorization.

221111222202221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17008555554030.

The product of its (nonzero) digits is 512, while the sum is 23.

Adding to 221111222202221 its reverse (122202222111122), we get a palindrome (343313444313343).

The spelling of 221111222202221 in words is "two hundred twenty-one trillion, one hundred eleven billion, two hundred twenty-two million, two hundred two thousand, two hundred twenty-one".