21201120221 has 2 divisors, whose sum is σ = 21201120222. Its totient is φ = 21201120220.

The previous prime is 21201120203. The next prime is 21201120233. The reversal of 21201120221 is 12202110212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17111517721 + 4089602500 = 130811^2 + 63950^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201120221 - 2¹⁰ = 21201119197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21201120196 and 21201120205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21201120271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600560110 + 10600560111.

It is an arithmetic number, because the mean of its divisors is an integer number (10600560111).

Almost surely, 2^21201120221 is an apocalyptic number.

It is an amenable number.

21201120221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201120221 is an equidigital number, since it uses as much as digits as its factorization.

21201120221 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 14.

Adding to 21201120221 its reverse (12202110212), we get a palindrome (33403230433).

It can be divided in two parts, 212011 and 20221, that added together give a palindrome (232232).

The spelling of 21201120221 in words is "twenty-one billion, two hundred one million, one hundred twenty thousand, two hundred twenty-one".