20001222022121 has 16 divisors (see below), whose sum is σ = 20684880760320. Its totient is φ = 19319981535360.

The previous prime is 20001222022003. The next prime is 20001222022139. The reversal of 20001222022121 is 12122022210002.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20001222022121 - 2²² = 20001217827817 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20001222022121.

It is not an unprimeable number, because it can be changed into a prime (20001222022151) 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, 83664866 + ... + 83903588.

It is an arithmetic number, because the mean of its divisors is an integer number (1292805047520).

Almost surely, 2^{20001222022121} is an apocalyptic number.

It is an amenable number.

20001222022121 is a deficient number, since it is larger than the sum of its proper divisors (683658738199).

20001222022121 is a wasteful number, since it uses less digits than its factorization.

20001222022121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243776.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 20001222022121 its reverse (12122022210002), we get a palindrome (32123244232123).

The spelling of 20001222022121 in words is "twenty trillion, one billion, two hundred twenty-two million, twenty-two thousand, one hundred twenty-one".