21200120220121 has 8 divisors (see below), whose sum is σ = 22318434072320. Its totient is φ = 20082058173072.

The previous prime is 21200120220113. The next prime is 21200120220137. The reversal of 21200120220121 is 12102202100212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21200120220121 - 2³ = 21200120220113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21200120220095 and 21200120220104.

It is not an unprimeable number, because it can be changed into a prime (21200120224121) 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, 62778450 + ... + 63115243.

It is an arithmetic number, because the mean of its divisors is an integer number (2789804259040).

Almost surely, 2^{21200120220121} is an apocalyptic number.

It is an amenable number.

21200120220121 is a deficient number, since it is larger than the sum of its proper divisors (1118313852199).

21200120220121 is a wasteful number, since it uses less digits than its factorization.

21200120220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125902575.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21200120220121 its reverse (12102202100212), we get a palindrome (33302322320333).

The spelling of 21200120220121 in words is "twenty-one trillion, two hundred billion, one hundred twenty million, two hundred twenty thousand, one hundred twenty-one".