19939444540 has 48 divisors (see below), whose sum is σ = 42588774144. Its totient is φ = 7839590400.

The previous prime is 19939444519. The next prime is 19939444541. The reversal of 19939444540 is 4544493991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19939444541) 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 15 ways as a sum of consecutive naturals, for example, 2065525 + ... + 2075155.

It is an arithmetic number, because the mean of its divisors is an integer number (887266128).

Almost surely, 2^19939444540 is an apocalyptic number.

19939444540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19939444540 is an abundant number, since it is smaller than the sum of its proper divisors (22649329604).

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

19939444540 is a wasteful number, since it uses less digits than its factorization.

19939444540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11398 (or 11396 counting only the distinct ones).

The product of its (nonzero) digits is 2799360, while the sum is 52.

The spelling of 19939444540 in words is "nineteen billion, nine hundred thirty-nine million, four hundred forty-four thousand, five hundred forty".