21122122120221 has 16 divisors (see below), whose sum is σ = 28202163289280. Its totient is φ = 14061749506560.

The previous prime is 21122122120217. The next prime is 21122122120261. The reversal of 21122122120221 is 12202122122112.

It is not a de Polignac number, because 21122122120221 - 2² = 21122122120217 is a prime.

It is a super-2 number, since 2×21122122120221² (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 (21122122120261) 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, 54079791 + ... + 54468963.

It is an arithmetic number, because the mean of its divisors is an integer number (1762635205580).

Almost surely, 2^{21122122120221} is an apocalyptic number.

It is an amenable number.

21122122120221 is a deficient number, since it is larger than the sum of its proper divisors (7080041169059).

21122122120221 is a wasteful number, since it uses less digits than its factorization.

21122122120221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414396.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21122122120221 its reverse (12202122122112), we get a palindrome (33324244242333).

The spelling of 21122122120221 in words is "twenty-one trillion, one hundred twenty-two billion, one hundred twenty-two million, one hundred twenty thousand, two hundred twenty-one".