20110121011221 has 16 divisors (see below), whose sum is σ = 26947419744960. Its totient is φ = 13339865347200.

The previous prime is 20110121011207. The next prime is 20110121011289. The reversal of 20110121011221 is 12211012101102.

It is a happy number.

It is not a de Polignac number, because 20110121011221 - 2¹⁰ = 20110121010197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20110121011221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20110121011291) 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, 9067555 + ... + 11065296.

It is an arithmetic number, because the mean of its divisors is an integer number (1684213734060).

Almost surely, 2^{20110121011221} is an apocalyptic number.

It is an amenable number.

20110121011221 is a deficient number, since it is larger than the sum of its proper divisors (6837298733739).

20110121011221 is a wasteful number, since it uses less digits than its factorization.

20110121011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20134516.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 20110121011221 its reverse (12211012101102), we get a palindrome (32321133112323).

The spelling of 20110121011221 in words is "twenty trillion, one hundred ten billion, one hundred twenty-one million, eleven thousand, two hundred twenty-one".