21122122220221 has 32 divisors (see below), whose sum is σ = 23460994252800. Its totient is φ = 18855717192000.

The previous prime is 21122122220183. The next prime is 21122122220239. The reversal of 21122122220221 is 12202222122112.

It is a cyclic number.

It is not a de Polignac number, because 21122122220221 - 2²⁵ = 21122088665789 is a prime.

It is a super-2 number, since 2×21122122220221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21122122220192 and 21122122220201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122122220261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1065741250 + ... + 1065761068.

It is an arithmetic number, because the mean of its divisors is an integer number (733156070400).

Almost surely, 2^{21122122220221} is an apocalyptic number.

It is an amenable number.

21122122220221 is a deficient number, since it is larger than the sum of its proper divisors (2338872032579).

21122122220221 is a wasteful number, since it uses less digits than its factorization.

21122122220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26521.

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

Adding to 21122122220221 its reverse (12202222122112), we get a palindrome (33324344342333).

The spelling of 21122122220221 in words is "twenty-one trillion, one hundred twenty-two billion, one hundred twenty-two million, two hundred twenty thousand, two hundred twenty-one".