21102211187 has 2 divisors, whose sum is σ = 21102211188. Its totient is φ = 21102211186.

The previous prime is 21102211181. The next prime is 21102211213. The reversal of 21102211187 is 78111220112.

It is a happy number.

It is an a-pointer prime, because the next prime (21102211213) can be obtained adding 21102211187 to its sum of digits (26).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21102211187 is a prime.

It is not a weakly prime, because it can be changed into another prime (21102211181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551105593 + 10551105594.

It is an arithmetic number, because the mean of its divisors is an integer number (10551105594).

Almost surely, 2^21102211187 is an apocalyptic number.

21102211187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102211187 is an equidigital number, since it uses as much as digits as its factorization.

21102211187 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 448, while the sum is 26.

Adding to 21102211187 its reverse (78111220112), we get a palindrome (99213431299).

The spelling of 21102211187 in words is "twenty-one billion, one hundred two million, two hundred eleven thousand, one hundred eighty-seven".