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1000000009 is a prime number

1000000009 has 2 divisors, whose sum is σ = 1000000010. Its totient is φ = 1000000008.

The previous prime is 1000000007. The next prime is 1000000021. The reversal of 1000000009 is 9000000001.

Subtracting from 1000000009 its sum of digits (10), we obtain a palindrome (999999999).

It can be divided in two parts, 100000000 and 9, that multiplied together give a square (900000000 = 300002).

It is a happy number.

1000000009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 985960000 + 14040009 = 31400^2 + 3747^2 .

It is an emirp because it is prime and its reverse (9000000001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1000000009 - 21 = 1000000007 is a prime.

Together with 1000000007, it forms a pair of twin primes.

1000000009 is a modest number, since divided by 9 gives 1 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 999999941 and 1000000004.

It is not a weakly prime, because it can be changed into another prime (1000000007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500000004 + 500000005.

It is an arithmetic number, because the mean of its divisors is an integer number (500000005).

Almost surely, 21000000009 is an apocalyptic number.

It is an amenable number.

1000000009 is a deficient number, since it is larger than the sum of its proper divisors (1).

1000000009 is an equidigital number, since it uses as much as digits as its factorization.

1000000009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9, while the sum is 10.

The square root of 1000000009 is about 31622.7767439863. The cubic root of 1000000009 is about 1000.0000030000. Note that the first 5 decimals are identical.

The spelling of 1000000009 in words is "one billion, nine", and thus it is an aban number and an uban number.