19987144992543 has 8 divisors (see below), whose sum is σ = 26649928083456. Its totient is φ = 13324562615000.

The previous prime is 19987144992539. The next prime is 19987144992589. The reversal of 19987144992543 is 34529944178991.

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 19987144992543 - 2² = 19987144992539 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19987144992743) 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, 49945833 + ... + 50344418.

It is an arithmetic number, because the mean of its divisors is an integer number (3331241010432).

Almost surely, 2^{19987144992543} is an apocalyptic number.

19987144992543 is a deficient number, since it is larger than the sum of its proper divisors (6662783090913).

19987144992543 is a wasteful number, since it uses less digits than its factorization.

19987144992543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100356685.

The product of its digits is 705438720, while the sum is 75.

The spelling of 19987144992543 in words is "nineteen trillion, nine hundred eighty-seven billion, one hundred forty-four million, nine hundred ninety-two thousand, five hundred forty-three".