21100120111 has 4 divisors (see below), whose sum is σ = 24114422992. Its totient is φ = 18085817232.

The previous prime is 21100120099. The next prime is 21100120127. The reversal of 21100120111 is 11102100112.

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

It is not a de Polignac number, because 21100120111 - 2⁵ = 21100120079 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 (21100120211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1507151430 + ... + 1507151443.

It is an arithmetic number, because the mean of its divisors is an integer number (6028605748).

Almost surely, 2^21100120111 is an apocalyptic number.

21100120111 is a deficient number, since it is larger than the sum of its proper divisors (3014302881).

21100120111 is an equidigital number, since it uses as much as digits as its factorization.

21100120111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3014302880.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 21100120111 its reverse (11102100112), we get a palindrome (32202220223).

The spelling of 21100120111 in words is "twenty-one billion, one hundred million, one hundred twenty thousand, one hundred eleven".