21122222112021 has 4 divisors (see below), whose sum is σ = 28162962816032. Its totient is φ = 14081481408012.

The previous prime is 21122222112011. The next prime is 21122222112097. The reversal of 21122222112021 is 12021122222112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21122222112021 - 2⁶ = 21122222111957 is a prime.

It is a super-2 number, since 2×21122222112021² (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 (21122222112001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3520370352001 + ... + 3520370352006.

It is an arithmetic number, because the mean of its divisors is an integer number (7040740704008).

Almost surely, 2^{21122222112021} is an apocalyptic number.

It is an amenable number.

21122222112021 is a deficient number, since it is larger than the sum of its proper divisors (7040740704011).

21122222112021 is an equidigital number, since it uses as much as digits as its factorization.

21122222112021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7040740704010.

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

Adding to 21122222112021 its reverse (12021122222112), we get a palindrome (33143344334133).

The spelling of 21122222112021 in words is "twenty-one trillion, one hundred twenty-two billion, two hundred twenty-two million, one hundred twelve thousand, twenty-one".