118191091 has 4 divisors (see below), whose sum is σ = 118313784. Its totient is φ = 118068400.

The previous prime is 118191083. The next prime is 118191097. The reversal of 118191091 is 190191811.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 118191091 - 2³ = 118191083 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (118191097) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59890 + ... + 61831.

It is an arithmetic number, because the mean of its divisors is an integer number (29578446).

Almost surely, 2^118191091 is an apocalyptic number.

118191091 is a deficient number, since it is larger than the sum of its proper divisors (122693).

118191091 is an equidigital number, since it uses as much as digits as its factorization.

118191091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122692.

The product of its (nonzero) digits is 648, while the sum is 31.

The square root of 118191091 is about 10871.5726093330. The cubic root of 118191091 is about 490.7514376339.

The spelling of 118191091 in words is "one hundred eighteen million, one hundred ninety-one thousand, ninety-one".