21111200010111 has 4 divisors (see below), whose sum is σ = 28148266680152. Its totient is φ = 14074133340072.

The previous prime is 21111200010101. The next prime is 21111200010149. The reversal of 21111200010111 is 11101000211112.

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

It is not a de Polignac number, because 21111200010111 - 2¹⁰ = 21111200009087 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 (21111200010101) 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, 3518533335016 + ... + 3518533335021.

It is an arithmetic number, because the mean of its divisors is an integer number (7037066670038).

Almost surely, 2^{21111200010111} is an apocalyptic number.

21111200010111 is a deficient number, since it is larger than the sum of its proper divisors (7037066670041).

21111200010111 is an equidigital number, since it uses as much as digits as its factorization.

21111200010111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7037066670040.

The product of its (nonzero) digits is 4, while the sum is 12.

Adding to 21111200010111 its reverse (11101000211112), we get a palindrome (32212200221223).

The spelling of 21111200010111 in words is "twenty-one trillion, one hundred eleven billion, two hundred million, ten thousand, one hundred eleven".