21222111020221 has 4 divisors (see below), whose sum is σ = 21440895670012. Its totient is φ = 21003326370432.

The previous prime is 21222111020207. The next prime is 21222111020237. The reversal of 21222111020221 is 12202011122212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16791464912121 + 4430646108100 = 4097739^2 + 2104910^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222111020221 - 2⁴¹ = 19023087764669 is a prime.

It is a super-2 number, since 2×21222111020221² (a number of 27 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 (21222111020321) 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, 109392324750 + ... + 109392324943.

It is an arithmetic number, because the mean of its divisors is an integer number (5360223917503).

Almost surely, 2^{21222111020221} is an apocalyptic number.

It is an amenable number.

21222111020221 is a deficient number, since it is larger than the sum of its proper divisors (218784649791).

21222111020221 is an equidigital number, since it uses as much as digits as its factorization.

21222111020221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218784649790.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21222111020221 its reverse (12202011122212), we get a palindrome (33424122142433).

The spelling of 21222111020221 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred eleven million, twenty thousand, two hundred twenty-one".