21101001101111 has 4 divisors (see below), whose sum is σ = 21103472821152. Its totient is φ = 21098529381072.

The previous prime is 21101001101051. The next prime is 21101001101123. The reversal of 21101001101111 is 11110110010112.

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 21101001101111 - 2²⁶ = 21100933992247 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101001101092 and 21101001101101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101001107111) 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, 1235847215 + ... + 1235864288.

It is an arithmetic number, because the mean of its divisors is an integer number (5275868205288).

Almost surely, 2^{21101001101111} is an apocalyptic number.

21101001101111 is a deficient number, since it is larger than the sum of its proper divisors (2471720041).

21101001101111 is an equidigital number, since it uses as much as digits as its factorization.

21101001101111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2471720040.

The product of its (nonzero) digits is 2, while the sum is 11.

Adding to 21101001101111 its reverse (11110110010112), we get a palindrome (32211111111223).

The spelling of 21101001101111 in words is "twenty-one trillion, one hundred one billion, one million, one hundred one thousand, one hundred eleven".