981744209 has 2 divisors, whose sum is σ = 981744210. Its totient is φ = 981744208.

The previous prime is 981744161. The next prime is 981744227. The reversal of 981744209 is 902447189.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 942305809 + 39438400 = 30697^2 + 6280^2 .

It is a cyclic number.

It is not a de Polignac number, because 981744209 - 2¹² = 981740113 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 981744209.

It is not a weakly prime, because it can be changed into another prime (981744229) 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 as a sum of consecutive naturals, namely, 490872104 + 490872105.

It is an arithmetic number, because the mean of its divisors is an integer number (490872105).

Almost surely, 2^981744209 is an apocalyptic number.

It is an amenable number.

981744209 is a deficient number, since it is larger than the sum of its proper divisors (1).

981744209 is an equidigital number, since it uses as much as digits as its factorization.

981744209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 44.

The square root of 981744209 is about 31332.7976567685. The cubic root of 981744209 is about 993.8773256999.

The spelling of 981744209 in words is "nine hundred eighty-one million, seven hundred forty-four thousand, two hundred nine".