118005991 has 2 divisors, whose sum is σ = 118005992. Its totient is φ = 118005990.

The previous prime is 118005989. The next prime is 118006001. The reversal of 118005991 is 199500811.

It is a weak prime.

It is an emirp because it is prime and its reverse (199500811) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 118005991 - 2¹ = 118005989 is a prime.

Together with 118005989, 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 (118005491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 59002995 + 59002996.

It is an arithmetic number, because the mean of its divisors is an integer number (59002996).

Almost surely, 2^118005991 is an apocalyptic number.

118005991 is a deficient number, since it is larger than the sum of its proper divisors (1).

118005991 is an equidigital number, since it uses as much as digits as its factorization.

118005991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 34.

The square root of 118005991 is about 10863.0562458270. The cubic root of 118005991 is about 490.4951138777.

The spelling of 118005991 in words is "one hundred eighteen million, five thousand, nine hundred ninety-one".