21002212111987 has 2 divisors, whose sum is σ = 21002212111988. Its totient is φ = 21002212111986.

The previous prime is 21002212111973. The next prime is 21002212112029. The reversal of 21002212111987 is 78911121220012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21002212111987 - 2¹¹ = 21002212109939 is a prime.

It is not a weakly prime, because it can be changed into another prime (21002212111927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501106055993 + 10501106055994.

It is an arithmetic number, because the mean of its divisors is an integer number (10501106055994).

Almost surely, 2^{21002212111987} is an apocalyptic number.

21002212111987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002212111987 is an equidigital number, since it uses as much as digits as its factorization.

21002212111987 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 37.

Adding to 21002212111987 its reverse (78911121220012), we get a palindrome (99913333331999).

The spelling of 21002212111987 in words is "twenty-one trillion, two billion, two hundred twelve million, one hundred eleven thousand, nine hundred eighty-seven".