961380809 has 2 divisors, whose sum is σ = 961380810. Its totient is φ = 961380808.

The previous prime is 961380793. The next prime is 961380899. The reversal of 961380809 is 908083169.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 641507584 + 319873225 = 25328^2 + 17885^2 .

It is a cyclic number.

It is not a de Polignac number, because 961380809 - 2⁴ = 961380793 is a prime.

It is a Sophie Germain prime.

It is a Chen 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 961380809.

It is not a weakly prime, because it can be changed into another prime (961380899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 480690404 + 480690405.

It is an arithmetic number, because the mean of its divisors is an integer number (480690405).

Almost surely, 2^961380809 is an apocalyptic number.

It is an amenable number.

961380809 is a deficient number, since it is larger than the sum of its proper divisors (1).

961380809 is an equidigital number, since it uses as much as digits as its factorization.

961380809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 961380809 is about 31006.1414722955. The cubic root of 961380809 is about 986.9575709039.

The spelling of 961380809 in words is "nine hundred sixty-one million, three hundred eighty thousand, eight hundred nine".