20111211021121 has 4 divisors (see below), whose sum is σ = 21939502932144. Its totient is φ = 18282919110100.

The previous prime is 20111211021113. The next prime is 20111211021173. The reversal of 20111211021121 is 12112011211102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20111211021121 - 2³ = 20111211021113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20111211021095 and 20111211021104.

It is not an unprimeable number, because it can be changed into a prime (20111211021521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 914145955495 + ... + 914145955516.

It is an arithmetic number, because the mean of its divisors is an integer number (5484875733036).

Almost surely, 2^{20111211021121} is an apocalyptic number.

It is an amenable number.

20111211021121 is a deficient number, since it is larger than the sum of its proper divisors (1828291911023).

20111211021121 is a wasteful number, since it uses less digits than its factorization.

20111211021121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1828291911022.

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

Adding to 20111211021121 its reverse (12112011211102), we get a palindrome (32223222232223).

The spelling of 20111211021121 in words is "twenty trillion, one hundred eleven billion, two hundred eleven million, twenty-one thousand, one hundred twenty-one".