221311212211 has 4 divisors (see below), whose sum is σ = 226457984632. Its totient is φ = 216164439792.

The previous prime is 221311212169. The next prime is 221311212289. The reversal of 221311212211 is 112212113122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 112212113122 = 2 ⋅56106056561.

It is a cyclic number.

It is not a de Polignac number, because 221311212211 - 2²⁵ = 221277657779 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221311215211) 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, 2573386146 + ... + 2573386231.

It is an arithmetic number, because the mean of its divisors is an integer number (56614496158).

Almost surely, 2^221311212211 is an apocalyptic number.

221311212211 is a deficient number, since it is larger than the sum of its proper divisors (5146772421).

221311212211 is an equidigital number, since it uses as much as digits as its factorization.

221311212211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5146772420.

The product of its digits is 96, while the sum is 19.

Adding to 221311212211 its reverse (112212113122), we get a palindrome (333523325333).

The spelling of 221311212211 in words is "two hundred twenty-one billion, three hundred eleven million, two hundred twelve thousand, two hundred eleven".