221100112211221 has 2 divisors, whose sum is σ = 221100112211222. Its totient is φ = 221100112211220.

The previous prime is 221100112211213. The next prime is 221100112211239. The reversal of 221100112211221 is 122112211001122.

It is a happy number.

221100112211221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 162447413376196 + 58652698835025 = 12745486^2 + 7658505^2 .

It is a cyclic number.

It is not a de Polignac number, because 221100112211221 - 2³ = 221100112211213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221100112011221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110550056105610 + 110550056105611.

It is an arithmetic number, because the mean of its divisors is an integer number (110550056105611).

Almost surely, 2^{221100112211221} is an apocalyptic number.

It is an amenable number.

221100112211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221100112211221 is an equidigital number, since it uses as much as digits as its factorization.

221100112211221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 221100112211221 its reverse (122112211001122), we get a palindrome (343212323212343).

The spelling of 221100112211221 in words is "two hundred twenty-one trillion, one hundred billion, one hundred twelve million, two hundred eleven thousand, two hundred twenty-one".