21111102221087 has 2 divisors, whose sum is σ = 21111102221088. Its totient is φ = 21111102221086.

The previous prime is 21111102221059. The next prime is 21111102221107. The reversal of 21111102221087 is 78012220111112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21111102221087 - 2¹⁰ = 21111102220063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21111102221017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555551110543 + 10555551110544.

It is an arithmetic number, because the mean of its divisors is an integer number (10555551110544).

Almost surely, 2^{21111102221087} is an apocalyptic number.

21111102221087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111102221087 is an equidigital number, since it uses as much as digits as its factorization.

21111102221087 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 896, while the sum is 29.

Adding to 21111102221087 its reverse (78012220111112), we get a palindrome (99123322332199).

The spelling of 21111102221087 in words is "twenty-one trillion, one hundred eleven billion, one hundred two million, two hundred twenty-one thousand, eighty-seven".