21120102001111 has 4 divisors (see below), whose sum is σ = 21518594491752. Its totient is φ = 20721609510472.

The previous prime is 21120102001099. The next prime is 21120102001127. The reversal of 21120102001111 is 11110020102112.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21120102001111 - 2²⁵ = 21120068446679 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21120102001091 and 21120102001100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120102001151) 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, 199246245241 + ... + 199246245346.

It is an arithmetic number, because the mean of its divisors is an integer number (5379648622938).

Almost surely, 2^{21120102001111} is an apocalyptic number.

21120102001111 is a deficient number, since it is larger than the sum of its proper divisors (398492490641).

21120102001111 is an equidigital number, since it uses as much as digits as its factorization.

21120102001111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398492490640.

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

Adding to 21120102001111 its reverse (11110020102112), we get a palindrome (32230122103223).

It can be divided in two parts, 21120102001 and 111, that added together give a palindrome (21120102112).

The spelling of 21120102001111 in words is "twenty-one trillion, one hundred twenty billion, one hundred two million, one thousand, one hundred eleven".