19864185856 has 44 divisors (see below), whose sum is σ = 40782266368. Its totient is φ = 9663639552.

The previous prime is 19864185853. The next prime is 19864185863. The reversal of 19864185856 is 65858146891.

It is a junction number, because it is equal to n+sod(n) for n = 19864185794 and 19864185803.

It is not an unprimeable number, because it can be changed into a prime (19864185853) 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 3 ways as a sum of consecutive naturals, for example, 224256 + ... + 300031.

Almost surely, 2^19864185856 is an apocalyptic number.

19864185856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19864185856 is an abundant number, since it is smaller than the sum of its proper divisors (20918080512).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19864185856 is an equidigital number, since it uses as much as digits as its factorization.

19864185856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524344 (or 524326 counting only the distinct ones).

The product of its digits is 16588800, while the sum is 61.

The spelling of 19864185856 in words is "nineteen billion, eight hundred sixty-four million, one hundred eighty-five thousand, eight hundred fifty-six".