509999999999 has 16 divisors (see below), whose sum is σ = 583712619840. Its totient is φ = 436501509120.

The previous prime is 509999999981. The next prime is 510000000007. The reversal of 509999999999 is 999999999905.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-509999999999 is a prime.

It is a super-9 number, since 9×509999999999⁹ (a number of 107 digits) contains 999999999 as substring.

509999999999 is a modest number, since divided by 999999 gives 509999 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (509999999599) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34655867 + ... + 34670579.

It is an arithmetic number, because the mean of its divisors is an integer number (36482038740).

Almost surely, 2^509999999999 is an apocalyptic number.

509999999999 is a deficient number, since it is larger than the sum of its proper divisors (73712619841).

509999999999 is a wasteful number, since it uses less digits than its factorization.

509999999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21650.

The product of its (nonzero) digits is 17433922005, while the sum is 95.

The spelling of 509999999999 in words is "five hundred nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-nine".