111857989 has 2 divisors, whose sum is σ = 111857990. Its totient is φ = 111857988.

The previous prime is 111857987. The next prime is 111858029. The reversal of 111857989 is 989758111.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 103184964 + 8673025 = 10158^2 + 2945^2 .

It is a cyclic number.

It is not a de Polignac number, because 111857989 - 2¹ = 111857987 is a prime.

Together with 111857987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111857983) 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, 55928994 + 55928995.

It is an arithmetic number, because the mean of its divisors is an integer number (55928995).

Almost surely, 2^111857989 is an apocalyptic number.

It is an amenable number.

111857989 is a deficient number, since it is larger than the sum of its proper divisors (1).

111857989 is an equidigital number, since it uses as much as digits as its factorization.

111857989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 49.

The square root of 111857989 is about 10576.2937270104. The cubic root of 111857989 is about 481.8246364811.

The spelling of 111857989 in words is "one hundred eleven million, eight hundred fifty-seven thousand, nine hundred eighty-nine".