509683491891 has 48 divisors (see below), whose sum is σ = 842959713024. Its totient is φ = 290702233152.

The previous prime is 509683491887. The next prime is 509683491893. The reversal of 509683491891 is 198194386905.

509683491891 is a `hidden beast` number, since 5 + 0 + 9 + 68 + 3 + 491 + 89 + 1 = 666.

It is not a de Polignac number, because 509683491891 - 2² = 509683491887 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (509683491893) 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 47 ways as a sum of consecutive naturals, for example, 99022780 + ... + 99027926.

It is an arithmetic number, because the mean of its divisors is an integer number (17561660688).

Almost surely, 2^509683491891 is an apocalyptic number.

509683491891 is a deficient number, since it is larger than the sum of its proper divisors (333276221133).

509683491891 is a wasteful number, since it uses less digits than its factorization.

509683491891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7800 (or 7797 counting only the distinct ones).

The product of its (nonzero) digits is 16796160, while the sum is 63.

The spelling of 509683491891 in words is "five hundred nine billion, six hundred eighty-three million, four hundred ninety-one thousand, eight hundred ninety-one".