19947888720 has 120 divisors (see below), whose sum is σ = 70517584800. Its totient is φ = 5039463168.

The previous prime is 19947888713. The next prime is 19947888721. The reversal of 19947888720 is 2788874991.

19947888720 is a `hidden beast` number, since 1 + 99 + 478 + 8 + 8 + 72 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19947888721) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 715410 + ... + 742769.

It is an arithmetic number, because the mean of its divisors is an integer number (587646540).

Almost surely, 2^19947888720 is an apocalyptic number.

19947888720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19947888720 is an abundant number, since it is smaller than the sum of its proper divisors (50569696080).

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

19947888720 is a wasteful number, since it uses less digits than its factorization.

19947888720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1458217 (or 1458208 counting only the distinct ones).

The product of its (nonzero) digits is 16257024, while the sum is 63.

The spelling of 19947888720 in words is "nineteen billion, nine hundred forty-seven million, eight hundred eighty-eight thousand, seven hundred twenty".