110011991 has 2 divisors, whose sum is σ = 110011992. Its totient is φ = 110011990.

The previous prime is 110011969. The next prime is 110011999. The reversal of 110011991 is 199110011.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 110011991 - 2¹⁸ = 109749847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (110011999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55005995 + 55005996.

It is an arithmetic number, because the mean of its divisors is an integer number (55005996).

Almost surely, 2^110011991 is an apocalyptic number.

110011991 is a deficient number, since it is larger than the sum of its proper divisors (1).

110011991 is an equidigital number, since it uses as much as digits as its factorization.

110011991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81, while the sum is 23.

The square root of 110011991 is about 10488.6601146190. The cubic root of 110011991 is about 479.1593953511.

It can be divided in two parts, 110011 and 991, that multiplied together give a palindrome (109020901).

The spelling of 110011991 in words is "one hundred ten million, eleven thousand, nine hundred ninety-one".