221020221221221 has 2 divisors, whose sum is σ = 221020221221222. Its totient is φ = 221020221221220.

The previous prime is 221020221221179. The next prime is 221020221221257. The reversal of 221020221221221 is 122122122020122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 174010685898721 + 47009535322500 = 13191311^2 + 6856350^2 .

It is a cyclic number.

It is not a de Polignac number, because 221020221221221 - 2¹⁵ = 221020221188453 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221020221221192 and 221020221221201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221020221221321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110510110610610 + 110510110610611.

It is an arithmetic number, because the mean of its divisors is an integer number (110510110610611).

Almost surely, 2^{221020221221221} is an apocalyptic number.

It is an amenable number.

221020221221221 is a deficient number, since it is larger than the sum of its proper divisors (1).

221020221221221 is an equidigital number, since it uses as much as digits as its factorization.

221020221221221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 22.

Adding to 221020221221221 its reverse (122122122020122), we get a palindrome (343142343241343).

The spelling of 221020221221221 in words is "two hundred twenty-one trillion, twenty billion, two hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".