221111021111221 has 2 divisors, whose sum is σ = 221111021111222. Its totient is φ = 221111021111220.

The previous prime is 221111021111147. The next prime is 221111021111243. The reversal of 221111021111221 is 122111120111122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123447432276100 + 97663588835121 = 11110690^2 + 9882489^2 .

It is a cyclic number.

It is not a de Polignac number, because 221111021111221 - 2³⁹ = 220561265297333 is a prime.

It is a super-2 number, since 2×221111021111221² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221111021171221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110555510555610 + 110555510555611.

It is an arithmetic number, because the mean of its divisors is an integer number (110555510555611).

Almost surely, 2^{221111021111221} is an apocalyptic number.

It is an amenable number.

221111021111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221111021111221 is an equidigital number, since it uses as much as digits as its factorization.

221111021111221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 19.

Adding to 221111021111221 its reverse (122111120111122), we get a palindrome (343222141222343).

The spelling of 221111021111221 in words is "two hundred twenty-one trillion, one hundred eleven billion, twenty-one million, one hundred eleven thousand, two hundred twenty-one".