981109 has 4 divisors (see below), whose sum is σ = 990220. Its totient is φ = 972000.

The previous prime is 981091. The next prime is 981133. The reversal of 981109 is 901189.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 901189 = 19 ⋅47431.

It can be written as a sum of positive squares in 2 ways, for example, as 418609 + 562500 = 647^2 + 750^2 .

It is a cyclic number.

It is not a de Polignac number, because 981109 - 2⁵ = 981077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981139) 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 3 ways as a sum of consecutive naturals, for example, 4392 + ... + 4609.

It is an arithmetic number, because the mean of its divisors is an integer number (247555).

2⁹⁸¹¹⁰⁹ is an apocalyptic number.

It is an amenable number.

981109 is a deficient number, since it is larger than the sum of its proper divisors (9111).

981109 is a wasteful number, since it uses less digits than its factorization.

981109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9110.

The product of its (nonzero) digits is 648, while the sum is 28.

The square root of 981109 is about 990.5094648715. The cubic root of 981109 is about 99.3662926326.

It can be divided in two parts, 981 and 109, that multiplied together give a square (106929 = 327²).

The spelling of 981109 in words is "nine hundred eighty-one thousand, one hundred nine".