19809659648 has 72 divisors (see below), whose sum is σ = 41026759200. Its totient is φ = 9534930944.

The previous prime is 19809659641. The next prime is 19809659651. The reversal of 19809659648 is 84695690891.

It is not an unprimeable number, because it can be changed into a prime (19809659641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2616893 + ... + 2624451.

It is an arithmetic number, because the mean of its divisors is an integer number (569816100).

Almost surely, 2^19809659648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19809659648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20513379600).

19809659648 is an abundant number, since it is smaller than the sum of its proper divisors (21217099552).

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

19809659648 is an equidigital number, since it uses as much as digits as its factorization.

19809659648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7957 (or 7943 counting only the distinct ones).

The product of its (nonzero) digits is 33592320, while the sum is 65.

The spelling of 19809659648 in words is "nineteen billion, eight hundred nine million, six hundred fifty-nine thousand, six hundred forty-eight".