981189109 has 2 divisors, whose sum is σ = 981189110. Its totient is φ = 981189108.

The previous prime is 981189107. The next prime is 981189197. The reversal of 981189109 is 901981189.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 506385009 + 474804100 = 22503^2 + 21790^2 .

It is a cyclic number.

It is not a de Polignac number, because 981189109 - 2¹ = 981189107 is a prime.

Together with 981189107, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (981189101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 490594554 + 490594555.

It is an arithmetic number, because the mean of its divisors is an integer number (490594555).

Almost surely, 2^981189109 is an apocalyptic number.

It is an amenable number.

981189109 is a deficient number, since it is larger than the sum of its proper divisors (1).

981189109 is an equidigital number, since it uses as much as digits as its factorization.

981189109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46656, while the sum is 46.

The square root of 981189109 is about 31323.9382741060. The cubic root of 981189109 is about 993.6899702726.

It can be divided in two parts, 981189 and 109, that multiplied together give a palindrome (106949601).

The spelling of 981189109 in words is "nine hundred eighty-one million, one hundred eighty-nine thousand, one hundred nine".