109115981 has 8 divisors (see below), whose sum is σ = 118025880. Its totient is φ = 100279872.

The previous prime is 109115977. The next prime is 109116017. The reversal of 109115981 is 189511901.

It can be written as a sum of positive squares in 4 ways, for example, as 17147881 + 91968100 = 4141^2 + 9590^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 109115981 - 2² = 109115977 is a prime.

It is a super-2 number, since 2×109115981² = 23812594619184722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (109115971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15350 + ... + 21303.

It is an arithmetic number, because the mean of its divisors is an integer number (14753235).

Almost surely, 2^109115981 is an apocalyptic number.

It is an amenable number.

109115981 is a deficient number, since it is larger than the sum of its proper divisors (8909899).

109115981 is a wasteful number, since it uses less digits than its factorization.

109115981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36895.

The product of its (nonzero) digits is 3240, while the sum is 35.

The square root of 109115981 is about 10445.8595146594. The cubic root of 109115981 is about 477.8549845164.

The spelling of 109115981 in words is "one hundred nine million, one hundred fifteen thousand, nine hundred eighty-one".