21121020011101 has 4 divisors (see below), whose sum is σ = 21126792362400. Its totient is φ = 21115247659804.

The previous prime is 21121020011087. The next prime is 21121020011149. The reversal of 21121020011101 is 10111002012112.

It is a happy number.

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 21121020011101 - 2²⁹ = 21120483140189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121020051101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2886170161 + ... + 2886177478.

It is an arithmetic number, because the mean of its divisors is an integer number (5281698090600).

Almost surely, 2^{21121020011101} is an apocalyptic number.

It is an amenable number.

21121020011101 is a deficient number, since it is larger than the sum of its proper divisors (5772351299).

21121020011101 is an equidigital number, since it uses as much as digits as its factorization.

21121020011101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5772351298.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21121020011101 its reverse (10111002012112), we get a palindrome (31232022023213).

The spelling of 21121020011101 in words is "twenty-one trillion, one hundred twenty-one billion, twenty million, eleven thousand, one hundred one".