21122120112221 has 16 divisors (see below), whose sum is σ = 21638548872000. Its totient is φ = 20611623035520.

The previous prime is 21122120112127. The next prime is 21122120112229. The reversal of 21122120112221 is 12221102122112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21122120112221 is a prime.

It is a super-2 number, since 2×21122120112221² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21122120112193 and 21122120112202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122120112229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 300639905 + ... + 300710153.

It is an arithmetic number, because the mean of its divisors is an integer number (1352409304500).

Almost surely, 2^{21122120112221} is an apocalyptic number.

It is an amenable number.

21122120112221 is a deficient number, since it is larger than the sum of its proper divisors (516428759779).

21122120112221 is a wasteful number, since it uses less digits than its factorization.

21122120112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112364.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21122120112221 its reverse (12221102122112), we get a palindrome (33343222234333).

The spelling of 21122120112221 in words is "twenty-one trillion, one hundred twenty-two billion, one hundred twenty million, one hundred twelve thousand, two hundred twenty-one".