19998565543 has 8 divisors (see below), whose sum is σ = 21854434320. Its totient is φ = 18148999680.

The previous prime is 19998565529. The next prime is 19998565549. The reversal of 19998565543 is 34556589991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19998565543 - 2⁵ = 19998565511 is a prime.

It is a Duffinian number.

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 polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1569088 + ... + 1581781.

It is an arithmetic number, because the mean of its divisors is an integer number (2731804290).

Almost surely, 2^19998565543 is an apocalyptic number.

19998565543 is a deficient number, since it is larger than the sum of its proper divisors (1855868777).

19998565543 is a wasteful number, since it uses less digits than its factorization.

19998565543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3151457.

The product of its digits is 52488000, while the sum is 64.

The spelling of 19998565543 in words is "nineteen billion, nine hundred ninety-eight million, five hundred sixty-five thousand, five hundred forty-three".