20001011021121 has 16 divisors (see below), whose sum is σ = 28720607509440. Its totient is φ = 12307797159360.

The previous prime is 20001011021087. The next prime is 20001011021143. The reversal of 20001011021121 is 12112011010002.

It is a de Polignac number, because none of the positive numbers 2^k-20001011021121 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20001011021097 and 20001011021106.

It is not an unprimeable number, because it can be changed into a prime (20001011071121) 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 15 ways as a sum of consecutive naturals, for example, 9836550 + ... + 11694431.

It is an arithmetic number, because the mean of its divisors is an integer number (1795037969340).

Almost surely, 2^{20001011021121} is an apocalyptic number.

It is an amenable number.

20001011021121 is a deficient number, since it is larger than the sum of its proper divisors (8719596488319).

20001011021121 is a wasteful number, since it uses less digits than its factorization.

20001011021121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21554816.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 20001011021121 its reverse (12112011010002), we get a palindrome (32113022031123).

The spelling of 20001011021121 in words is "twenty trillion, one billion, eleven million, twenty-one thousand, one hundred twenty-one".