19656543488 has 144 divisors (see below), whose sum is σ = 43109627904. Its totient is φ = 8904867840.

The previous prime is 19656543481. The next prime is 19656543523. The reversal of 19656543488 is 88434565691.

It is a super-2 number, since 2×19656543488² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19656543481) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49512506 + ... + 49512902.

It is an arithmetic number, because the mean of its divisors is an integer number (299372416).

Almost surely, 2^19656543488 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 19656543488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21554813952).

19656543488 is an abundant number, since it is smaller than the sum of its proper divisors (23453084416).

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

19656543488 is a wasteful number, since it uses less digits than its factorization.

19656543488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 828 (or 814 counting only the distinct ones).

The product of its digits is 24883200, while the sum is 59.

The spelling of 19656543488 in words is "nineteen billion, six hundred fifty-six million, five hundred forty-three thousand, four hundred eighty-eight".