21122112022221 has 32 divisors (see below), whose sum is σ = 32482518681600. Its totient is φ = 11959023067200.

The previous prime is 21122112022211. The next prime is 21122112022223. The reversal of 21122112022221 is 12222021122112.

It is not a de Polignac number, because 21122112022221 - 2¹⁸ = 21122111760077 is a prime.

It is a super-2 number, since 2×21122112022221² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122112022223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7328211 + ... + 9795248.

It is an arithmetic number, because the mean of its divisors is an integer number (1015078708800).

Almost surely, 2^{21122112022221} is an apocalyptic number.

21122112022221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21122112022221 is a deficient number, since it is larger than the sum of its proper divisors (11360406659379).

21122112022221 is a wasteful number, since it uses less digits than its factorization.

21122112022221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17124009.

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

Adding to 21122112022221 its reverse (12222021122112), we get a palindrome (33344133144333).

The spelling of 21122112022221 in words is "twenty-one trillion, one hundred twenty-two billion, one hundred twelve million, twenty-two thousand, two hundred twenty-one".