19998565542 has 24 divisors (see below), whose sum is σ = 44064638280. Its totient is φ = 6553201920.

The previous prime is 19998565529. The next prime is 19998565549. The reversal of 19998565542 is 24556589991.

19998565542 is a `hidden beast` number, since 1 + 9 + 9 + 9 + 85 + 6 + 5 + 542 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 19998565542.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19998565549) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 9414459 + ... + 9416582.

It is an arithmetic number, because the mean of its divisors is an integer number (1836026595).

Almost surely, 2^19998565542 is an apocalyptic number.

19998565542 is an abundant number, since it is smaller than the sum of its proper divisors (24066072738).

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

19998565542 is a wasteful number, since it uses less digits than its factorization.

19998565542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18831108 (or 18831105 counting only the distinct ones).

The product of its digits is 34992000, while the sum is 63.

The spelling of 19998565542 in words is "nineteen billion, nine hundred ninety-eight million, five hundred sixty-five thousand, five hundred forty-two".