111668981 has 2 divisors, whose sum is σ = 111668982. Its totient is φ = 111668980.

The previous prime is 111668969. The next prime is 111669017. The reversal of 111668981 is 189866111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99002500 + 12666481 = 9950^2 + 3559^2 .

It is a cyclic number.

It is not a de Polignac number, because 111668981 - 2⁶ = 111668917 is a prime.

It is a super-2 number, since 2×111668981² = 24939922635156722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen 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 (111668911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55834490 + 55834491.

It is an arithmetic number, because the mean of its divisors is an integer number (55834491).

Almost surely, 2^111668981 is an apocalyptic number.

It is an amenable number.

111668981 is a deficient number, since it is larger than the sum of its proper divisors (1).

111668981 is an equidigital number, since it uses as much as digits as its factorization.

111668981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 41.

The square root of 111668981 is about 10567.3544939119. The cubic root of 111668981 is about 481.5531015546.

The spelling of 111668981 in words is "one hundred eleven million, six hundred sixty-eight thousand, nine hundred eighty-one".