21220212202221 has 32 divisors (see below), whose sum is σ = 30023692554240. Its totient is φ = 13309478334656.

The previous prime is 21220212202171. The next prime is 21220212202261. The reversal of 21220212202221 is 12220221202212.

It is a cyclic number.

It is not a de Polignac number, because 21220212202221 - 2¹³ = 21220212194029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220212202261) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10502601 + ... + 12359006.

It is an arithmetic number, because the mean of its divisors is an integer number (938240392320).

Almost surely, 2^{21220212202221} is an apocalyptic number.

It is an amenable number.

21220212202221 is a deficient number, since it is larger than the sum of its proper divisors (8803480352019).

21220212202221 is a wasteful number, since it uses less digits than its factorization.

21220212202221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22861913.

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 21220212202221 its reverse (12220221202212), we get a palindrome (33440433404433).

The spelling of 21220212202221 in words is "twenty-one trillion, two hundred twenty billion, two hundred twelve million, two hundred two thousand, two hundred twenty-one".