111111989 has 2 divisors, whose sum is σ = 111111990. Its totient is φ = 111111988.

The previous prime is 111111953. The next prime is 111112003. The reversal of 111111989 is 989111111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 56100100 + 55011889 = 7490^2 + 7417^2 .

It is a cyclic number.

It is not a de Polignac number, because 111111989 - 2²⁰ = 110063413 is a prime.

It is a super-2 number, since 2×111111989² = 24691748199072242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111111089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55555994 + 55555995.

It is an arithmetic number, because the mean of its divisors is an integer number (55555995).

Almost surely, 2^111111989 is an apocalyptic number.

It is an amenable number.

111111989 is a deficient number, since it is larger than the sum of its proper divisors (1).

111111989 is an equidigital number, since it uses as much as digits as its factorization.

111111989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 648, while the sum is 32.

The square root of 111111989 is about 10540.9671757387. The cubic root of 111111989 is about 480.7511229007.

The spelling of 111111989 in words is "one hundred eleven million, one hundred eleven thousand, nine hundred eighty-nine".