20001221010111 has 32 divisors (see below), whose sum is σ = 29333954373120. Its totient is φ = 12121607541120.

The previous prime is 20001221010073. The next prime is 20001221010139. The reversal of 20001221010111 is 11101012210002.

It is not a de Polignac number, because 20001221010111 - 2¹⁸ = 20001220747967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20001221080111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 253368295 + ... + 253447223.

It is an arithmetic number, because the mean of its divisors is an integer number (916686074160).

Almost surely, 2^{20001221010111} is an apocalyptic number.

20001221010111 is a deficient number, since it is larger than the sum of its proper divisors (9332733363009).

20001221010111 is an equidigital number, since it uses as much as digits as its factorization.

20001221010111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142428 (or 142406 counting only the distinct ones).

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

Adding to 20001221010111 its reverse (11101012210002), we get a palindrome (31102233220113).

The spelling of 20001221010111 in words is "twenty trillion, one billion, two hundred twenty-one million, ten thousand, one hundred eleven".