1009999999 has 2 divisors, whose sum is σ = 1010000000. Its totient is φ = 1009999998.

The previous prime is 1009999979. The next prime is 1010000011. The reversal of 1009999999 is 9999999001.

It is a strong prime.

It is an emirp because it is prime and its reverse (9999999001) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1009999999 is a prime.

1009999999 is a modest number, since divided by 99999 gives 10099 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 1009999999.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1009999909) 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, 504999999 + 505000000.

It is an arithmetic number, because the mean of its divisors is an integer number (505000000).

Almost surely, 2^1009999999 is an apocalyptic number.

1009999999 is a deficient number, since it is larger than the sum of its proper divisors (1).

1009999999 is an equidigital number, since it uses as much as digits as its factorization.

1009999999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4782969, while the sum is 64.

The square root of 1009999999 is about 31780.4971484085. The cubic root of 1009999999 is about 1003.3222832110.

It can be divided in two parts, 100999 and 9999, that multiplied together give a palindrome (1009889001).

The spelling of 1009999999 in words is "one billion, nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".