20001201022121 has 6 divisors (see below), whose sum is σ = 21984791206266. Its totient is φ = 18182910020000.

The previous prime is 20001201022073. The next prime is 20001201022219. The reversal of 20001201022121 is 12122010210002.

It can be written as a sum of positive squares in only one way, i.e., 10401985994521 + 9599215027600 = 3225211^2 + 3098260^2 .

It is not a de Polignac number, because 20001201022121 - 2¹⁸ = 20001200759977 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20001201022096 and 20001201022105.

It is not an unprimeable number, because it can be changed into a prime (20001201021121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 82649590880 + ... + 82649591121.

It is an arithmetic number, because the mean of its divisors is an integer number (3664131867711).

Almost surely, 2^{20001201022121} is an apocalyptic number.

It is an amenable number.

20001201022121 is a deficient number, since it is larger than the sum of its proper divisors (1983590184145).

20001201022121 is a wasteful number, since it uses less digits than its factorization.

20001201022121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165299182023 (or 165299182012 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 20001201022121 its reverse (12122010210002), we get a palindrome (32123211232123).

The spelling of 20001201022121 in words is "twenty trillion, one billion, two hundred one million, twenty-two thousand, one hundred twenty-one".