111221218987 has 2 divisors, whose sum is σ = 111221218988. Its totient is φ = 111221218986.

The previous prime is 111221218981. The next prime is 111221219017. The reversal of 111221218987 is 789812122111.

It is a weak prime.

It is an emirp because it is prime and its reverse (789812122111) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111221218987 is a prime.

It is not a weakly prime, because it can be changed into another prime (111221218981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55610609493 + 55610609494.

It is an arithmetic number, because the mean of its divisors is an integer number (55610609494).

Almost surely, 2^111221218987 is an apocalyptic number.

111221218987 is a deficient number, since it is larger than the sum of its proper divisors (1).

111221218987 is an equidigital number, since it uses as much as digits as its factorization.

111221218987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 43.

The spelling of 111221218987 in words is "one hundred eleven billion, two hundred twenty-one million, two hundred eighteen thousand, nine hundred eighty-seven".