1908394009 has 2 divisors, whose sum is σ = 1908394010. Its totient is φ = 1908394008.

The previous prime is 1908393989. The next prime is 1908394043. The reversal of 1908394009 is 9004938091.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1332250000 + 576144009 = 36500^2 + 24003^2 .

It is an emirp because it is prime and its reverse (9004938091) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1908394009 is a prime.

It is not a weakly prime, because it can be changed into another prime (1908394049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 954197004 + 954197005.

It is an arithmetic number, because the mean of its divisors is an integer number (954197005).

Almost surely, 2^1908394009 is an apocalyptic number.

It is an amenable number.

1908394009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1908394009 is an equidigital number, since it uses as much as digits as its factorization.

1908394009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 1908394009 is about 43685.1692110721. The cubic root of 1908394009 is about 1240.3835981518.

The spelling of 1908394009 in words is "one billion, nine hundred eight million, three hundred ninety-four thousand, nine".