21211100200111 has 4 divisors (see below), whose sum is σ = 21211152300352. Its totient is φ = 21211048099872.

The previous prime is 21211100200057. The next prime is 21211100200127. The reversal of 21211100200111 is 11100200111212.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21211100200111 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211100200091 and 21211100200100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211100200181) 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, 25434591 + ... + 26255296.

It is an arithmetic number, because the mean of its divisors is an integer number (5302788075088).

Almost surely, 2^{21211100200111} is an apocalyptic number.

21211100200111 is a deficient number, since it is larger than the sum of its proper divisors (52100241).

21211100200111 is an equidigital number, since it uses as much as digits as its factorization.

21211100200111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52100240.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21211100200111 its reverse (11100200111212), we get a palindrome (32311300311323).

It can be divided in two parts, 212 and 11100200111, that multiplied together give a palindrome (2353242423532).

The spelling of 21211100200111 in words is "twenty-one trillion, two hundred eleven billion, one hundred million, two hundred thousand, one hundred eleven".