21111212200111 has 4 divisors (see below), whose sum is σ = 23030413309224. Its totient is φ = 19192011091000.

The previous prime is 21111212200109. The next prime is 21111212200139. The reversal of 21111212200111 is 11100221211112.

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

It is not a de Polignac number, because 21111212200111 - 2¹ = 21111212200109 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 (21111212200511) 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, 959600554540 + ... + 959600554561.

It is an arithmetic number, because the mean of its divisors is an integer number (5757603327306).

Almost surely, 2^{21111212200111} is an apocalyptic number.

21111212200111 is a deficient number, since it is larger than the sum of its proper divisors (1919201109113).

21111212200111 is a wasteful number, since it uses less digits than its factorization.

21111212200111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1919201109112.

The product of its (nonzero) digits is 16, while the sum is 16.

Adding to 21111212200111 its reverse (11100221211112), we get a palindrome (32211433411223).

The spelling of 21111212200111 in words is "twenty-one trillion, one hundred eleven billion, two hundred twelve million, two hundred thousand, one hundred eleven".