111969989 has 2 divisors, whose sum is σ = 111969990. Its totient is φ = 111969988.

The previous prime is 111969959. The next prime is 111970009. The reversal of 111969989 is 989969111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111302500 + 667489 = 10550^2 + 817^2 .

It is an emirp because it is prime and its reverse (989969111) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111969989 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 111969989.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111969919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55984994 + 55984995.

It is an arithmetic number, because the mean of its divisors is an integer number (55984995).

Almost surely, 2^111969989 is an apocalyptic number.

It is an amenable number.

111969989 is a deficient number, since it is larger than the sum of its proper divisors (1).

111969989 is an equidigital number, since it uses as much as digits as its factorization.

111969989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 314928, while the sum is 53.

The square root of 111969989 is about 10581.5872627881. The cubic root of 111969989 is about 481.9853949535.

The spelling of 111969989 in words is "one hundred eleven million, nine hundred sixty-nine thousand, nine hundred eighty-nine".