499999999581 has 96 divisors (see below), whose sum is σ = 787510563840. Its totient is φ = 316658160000.

The previous prime is 499999999571. The next prime is 499999999643. The reversal of 499999999581 is 185999999994.

It is not a de Polignac number, because 499999999581 - 2¹¹ = 499999997533 is a prime.

It is a super-2 number, since 2×499999999581² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 499999999491 and 499999999500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (499999999501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 153797206 + ... + 153800456.

It is an arithmetic number, because the mean of its divisors is an integer number (8203235040).

Almost surely, 2^499999999581 is an apocalyptic number.

499999999581 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

499999999581 is a deficient number, since it is larger than the sum of its proper divisors (287510564259).

499999999581 is a wasteful number, since it uses less digits than its factorization.

499999999581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3709 (or 3697 counting only the distinct ones).

The product of its digits is 6887475360, while the sum is 90.

The spelling of 499999999581 in words is "four hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, five hundred eighty-one".