21220022122121 has 4 divisors (see below), whose sum is σ = 21279130819200. Its totient is φ = 21160913425044.

The previous prime is 21220022122111. The next prime is 21220022122129. The reversal of 21220022122121 is 12122122002212.

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 a cyclic number.

It is not a de Polignac number, because 21220022122121 - 2³⁰ = 21218948380297 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220022122093 and 21220022122102.

It is not an unprimeable number, because it can be changed into a prime (21220022122129) 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 3 ways as a sum of consecutive naturals, for example, 29554348001 + ... + 29554348718.

It is an arithmetic number, because the mean of its divisors is an integer number (5319782704800).

Almost surely, 2^{21220022122121} is an apocalyptic number.

It is an amenable number.

21220022122121 is a deficient number, since it is larger than the sum of its proper divisors (59108697079).

21220022122121 is an equidigital number, since it uses as much as digits as its factorization.

21220022122121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59108697078.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21220022122121 its reverse (12122122002212), we get a palindrome (33342144124333).

The spelling of 21220022122121 in words is "twenty-one trillion, two hundred twenty billion, twenty-two million, one hundred twenty-two thousand, one hundred twenty-one".