21111200211187 has 2 divisors, whose sum is σ = 21111200211188. Its totient is φ = 21111200211186.

The previous prime is 21111200211181. The next prime is 21111200211203. The reversal of 21111200211187 is 78111200211112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21111200211187 is a prime.

It is not a weakly prime, because it can be changed into another prime (21111200211181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555600105593 + 10555600105594.

It is an arithmetic number, because the mean of its divisors is an integer number (10555600105594).

Almost surely, 2^{21111200211187} is an apocalyptic number.

21111200211187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111200211187 is an equidigital number, since it uses as much as digits as its factorization.

21111200211187 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 448, while the sum is 28.

Adding to 21111200211187 its reverse (78111200211112), we get a palindrome (99222400422299).

The spelling of 21111200211187 in words is "twenty-one trillion, one hundred eleven billion, two hundred million, two hundred eleven thousand, one hundred eighty-seven".