21002112111187 has 2 divisors, whose sum is σ = 21002112111188. Its totient is φ = 21002112111186.

The previous prime is 21002112111173. The next prime is 21002112111203. The reversal of 21002112111187 is 78111121120012.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21002112111187 is a prime.

It is not a weakly prime, because it can be changed into another prime (21002112111587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501056055593 + 10501056055594.

It is an arithmetic number, because the mean of its divisors is an integer number (10501056055594).

Almost surely, 2^{21002112111187} is an apocalyptic number.

21002112111187 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002112111187 is an equidigital number, since it uses as much as digits as its factorization.

21002112111187 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 28.

Adding to 21002112111187 its reverse (78111121120012), we get a palindrome (99113233231199).

The spelling of 21002112111187 in words is "twenty-one trillion, two billion, one hundred twelve million, one hundred eleven thousand, one hundred eighty-seven".