21001110220121 has 16 divisors (see below), whose sum is σ = 23442153338880. Its totient is φ = 18721164080640.

The previous prime is 21001110220117. The next prime is 21001110220133. The reversal of 21001110220121 is 12102201110012.

It is not a de Polignac number, because 21001110220121 - 2² = 21001110220117 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21001110220096 and 21001110220105.

It is not an unprimeable number, because it can be changed into a prime (21001110220151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 423914636 + ... + 423964173.

It is an arithmetic number, because the mean of its divisors is an integer number (1465134583680).

Almost surely, 2^{21001110220121} is an apocalyptic number.

It is an amenable number.

21001110220121 is a deficient number, since it is larger than the sum of its proper divisors (2441043118759).

21001110220121 is a wasteful number, since it uses less digits than its factorization.

21001110220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 847878904.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21001110220121 its reverse (12102201110012), we get a palindrome (33103311330133).

The spelling of 21001110220121 in words is "twenty-one trillion, one billion, one hundred ten million, two hundred twenty thousand, one hundred twenty-one".