211222221221221 has 4 divisors (see below), whose sum is σ = 241396824252832. Its totient is φ = 181047618189612.

The previous prime is 211222221221177. The next prime is 211222221221239. The reversal of 211222221221221 is 122122122222112.

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 211222221221221 - 2⁷ = 211222221221093 is a prime.

It is a super-2 number, since 2×211222221221221² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211222221221821) 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, 15087301515795 + ... + 15087301515808.

It is an arithmetic number, because the mean of its divisors is an integer number (60349206063208).

Almost surely, 2^{211222221221221} is an apocalyptic number.

It is an amenable number.

211222221221221 is a deficient number, since it is larger than the sum of its proper divisors (30174603031611).

211222221221221 is an equidigital number, since it uses as much as digits as its factorization.

211222221221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30174603031610.

The product of its digits is 1024, while the sum is 25.

Adding to 211222221221221 its reverse (122122122222112), we get a palindrome (333344343443333).

The spelling of 211222221221221 in words is "two hundred eleven trillion, two hundred twenty-two billion, two hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".