118228991 has 4 divisors (see below), whose sum is σ = 118265184. Its totient is φ = 118192800.

The previous prime is 118228961. The next prime is 118229011. The reversal of 118228991 is 199822811.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199822811 = 17 ⋅11754283.

It is a cyclic number.

It is not a de Polignac number, because 118228991 - 2¹⁴ = 118212607 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (118228961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12650 + ... + 19911.

It is an arithmetic number, because the mean of its divisors is an integer number (29566296).

Almost surely, 2^118228991 is an apocalyptic number.

118228991 is a deficient number, since it is larger than the sum of its proper divisors (36193).

118228991 is an equidigital number, since it uses as much as digits as its factorization.

118228991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36192.

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

The square root of 118228991 is about 10873.3155477067. The cubic root of 118228991 is about 490.8038879824.

The spelling of 118228991 in words is "one hundred eighteen million, two hundred twenty-eight thousand, nine hundred ninety-one".