108721091 has 4 divisors (see below), whose sum is σ = 108744672. Its totient is φ = 108697512.

The previous prime is 108721079. The next prime is 108721111. The reversal of 108721091 is 190127801.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190127801 = 53 ⋅3587317.

It is a cyclic number.

It is not a de Polignac number, because 108721091 - 2¹⁴ = 108704707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (108723091) 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, 2360 + ... + 14933.

It is an arithmetic number, because the mean of its divisors is an integer number (27186168).

Almost surely, 2^108721091 is an apocalyptic number.

108721091 is a deficient number, since it is larger than the sum of its proper divisors (23581).

108721091 is an equidigital number, since it uses as much as digits as its factorization.

108721091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23580.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 108721091 is about 10426.9406347212. The cubic root of 108721091 is about 477.2778364007.

Adding to 108721091 its reverse (190127801), we get a palindrome (298848892).

The spelling of 108721091 in words is "one hundred eight million, seven hundred twenty-one thousand, ninety-one".