21221200220121 has 24 divisors (see below), whose sum is σ = 34556714168480. Its totient is φ = 12861333464760.

The previous prime is 21221200220063. The next prime is 21221200220179. The reversal of 21221200220121 is 12102200212212.

It is a happy number.

21221200220121 is a `hidden beast` number, since 2 + 1 + 221 + 200 + 220 + 1 + 21 = 666.

It is an interprime number because it is at equal distance from previous prime (21221200220063) and next prime (21221200220179).

It is not a de Polignac number, because 21221200220121 - 2¹¹ = 21221200218073 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221200220094 and 21221200220103.

It is not an unprimeable number, because it can be changed into a prime (21221220220121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3247808215 + ... + 3247814748.

Almost surely, 2^{21221200220121} is an apocalyptic number.

It is an amenable number.

21221200220121 is a deficient number, since it is larger than the sum of its proper divisors (13335513948359).

21221200220121 is a wasteful number, since it uses less digits than its factorization.

21221200220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6495622994 (or 6495622977 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21221200220121 its reverse (12102200212212), we get a palindrome (33323400432333).

The spelling of 21221200220121 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred million, two hundred twenty thousand, one hundred twenty-one".