21000120000111 has 24 divisors (see below), whose sum is σ = 36174119754240. Its totient is φ = 11478326458896.

The previous prime is 21000120000061. The next prime is 21000120000113. The reversal of 21000120000111 is 11100002100012.

It is a happy number.

It is not a de Polignac number, because 21000120000111 - 2¹¹ = 21000119998063 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21000120000093 and 21000120000102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21000120000113) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7246416771 + ... + 7246419668.

It is an arithmetic number, because the mean of its divisors is an integer number (1507254989760).

Almost surely, 2^{21000120000111} is an apocalyptic number.

21000120000111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21000120000111 is a deficient number, since it is larger than the sum of its proper divisors (15173999754129).

21000120000111 is a wasteful number, since it uses less digits than its factorization.

21000120000111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14492836475 (or 14492836472 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21000120000111 its reverse (11100002100012), we get a palindrome (32100122100123).

The spelling of 21000120000111 in words is "twenty-one trillion, one hundred twenty million, one hundred eleven", and thus it is an aban number.