111553991 has 2 divisors, whose sum is σ = 111553992. Its totient is φ = 111553990.

The previous prime is 111553963. The next prime is 111554041. The reversal of 111553991 is 199355111.

It is a weak prime.

It is an emirp because it is prime and its reverse (199355111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 111553991 - 2¹⁴ = 111537607 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111553931) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55776995 + 55776996.

It is an arithmetic number, because the mean of its divisors is an integer number (55776996).

Almost surely, 2^111553991 is an apocalyptic number.

111553991 is a deficient number, since it is larger than the sum of its proper divisors (1).

111553991 is an equidigital number, since it uses as much as digits as its factorization.

111553991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6075, while the sum is 35.

The square root of 111553991 is about 10561.9122795070. The cubic root of 111553991 is about 481.3877533132.

The spelling of 111553991 in words is "one hundred eleven million, five hundred fifty-three thousand, nine hundred ninety-one".