21011111000111 has 4 divisors (see below), whose sum is σ = 21057906348000. Its totient is φ = 20964315652224.

The previous prime is 21011111000071. The next prime is 21011111000119. The reversal of 21011111000111 is 11100011111012.

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 21011111000111 - 2¹⁴ = 21011110983727 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21011111000092 and 21011111000101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011111000119) 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 3 ways as a sum of consecutive naturals, for example, 23397673271 + ... + 23397674168.

It is an arithmetic number, because the mean of its divisors is an integer number (5264476587000).

Almost surely, 2^{21011111000111} is an apocalyptic number.

21011111000111 is a deficient number, since it is larger than the sum of its proper divisors (46795347889).

21011111000111 is an equidigital number, since it uses as much as digits as its factorization.

21011111000111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46795347888.

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

Adding to 21011111000111 its reverse (11100011111012), we get a palindrome (32111122111123).

The spelling of 21011111000111 in words is "twenty-one trillion, eleven billion, one hundred eleven million, one hundred eleven", and thus it is an aban number.