21022121022221 has 8 divisors (see below), whose sum is σ = 23553039769824. Its totient is φ = 18594505080720.

The previous prime is 21022121022211. The next prime is 21022121022241. The reversal of 21022121022221 is 12222012122012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21022121022221 is a prime.

It is a super-2 number, since 2×21022121022221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21022121022193 and 21022121022202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022121022211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25825701095 + ... + 25825701908.

It is an arithmetic number, because the mean of its divisors is an integer number (2944129971228).

Almost surely, 2^{21022121022221} is an apocalyptic number.

It is an amenable number.

21022121022221 is a deficient number, since it is larger than the sum of its proper divisors (2530918747603).

21022121022221 is a wasteful number, since it uses less digits than its factorization.

21022121022221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51651403051.

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

Adding to 21022121022221 its reverse (12222012122012), we get a palindrome (33244133144233).

The spelling of 21022121022221 in words is "twenty-one trillion, twenty-two billion, one hundred twenty-one million, twenty-two thousand, two hundred twenty-one".