108867991 has 4 divisors (see below), whose sum is σ = 108891000. Its totient is φ = 108844984.

The previous prime is 108867977. The next prime is 108868003. The reversal of 108867991 is 199768801.

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 108867991 - 2¹⁷ = 108736919 is a prime.

It is a Smith number, since the sum of its digits (49) 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 a congruent number.

It is not an unprimeable number, because it can be changed into a prime (108867961) 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, 1516 + ... + 14833.

It is an arithmetic number, because the mean of its divisors is an integer number (27222750).

Almost surely, 2^108867991 is an apocalyptic number.

108867991 is a deficient number, since it is larger than the sum of its proper divisors (23009).

108867991 is an equidigital number, since it uses as much as digits as its factorization.

108867991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23008.

The product of its (nonzero) digits is 217728, while the sum is 49.

The square root of 108867991 is about 10433.9825090902. The cubic root of 108867991 is about 477.4926998327.

The spelling of 108867991 in words is "one hundred eight million, eight hundred sixty-seven thousand, nine hundred ninety-one".