999900002509 has 2 divisors, whose sum is σ = 999900002510. Its totient is φ = 999900002508.

The previous prime is 999900002501. The next prime is 999900002531. The reversal of 999900002509 is 905200009999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 999900002500 + 9 = 999950^2 + 3^2 .

It is a cyclic number.

It is not a de Polignac number, because 999900002509 - 2³ = 999900002501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999900002501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499950001254 + 499950001255.

It is an arithmetic number, because the mean of its divisors is an integer number (499950001255).

Almost surely, 2^999900002509 is an apocalyptic number.

It is an amenable number.

999900002509 is a deficient number, since it is larger than the sum of its proper divisors (1).

999900002509 is an equidigital number, since it uses as much as digits as its factorization.

999900002509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 590490, while the sum is 52.

The spelling of 999900002509 in words is "nine hundred ninety-nine billion, nine hundred million, two thousand, five hundred nine".