19873544640 has 56 divisors (see below), whose sum is σ = 63098507280. Its totient is φ = 5299611648.

The previous prime is 19873544633. The next prime is 19873544671. The reversal of 19873544640 is 4644537891.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10349845 + ... + 10351764.

Almost surely, 2^19873544640 is an apocalyptic number.

19873544640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19873544640 is an abundant number, since it is smaller than the sum of its proper divisors (43224962640).

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

19873544640 is a wasteful number, since it uses less digits than its factorization.

19873544640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20701629 (or 20701619 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 51.

The spelling of 19873544640 in words is "nineteen billion, eight hundred seventy-three million, five hundred forty-four thousand, six hundred forty".