18821291376543 has 16 divisors (see below), whose sum is σ = 25965725510880. Its totient is φ = 12112369867136.

The previous prime is 18821291376539. The next prime is 18821291376571. The reversal of 18821291376543 is 34567319212881.

It is a cyclic number.

It is not a de Polignac number, because 18821291376543 - 2² = 18821291376539 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18821291376523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21754980 + ... + 22603577.

It is an arithmetic number, because the mean of its divisors is an integer number (1622857844430).

Almost surely, 2^{18821291376543} is an apocalyptic number.

18821291376543 is a deficient number, since it is larger than the sum of its proper divisors (7144434134337).

18821291376543 is a wasteful number, since it uses less digits than its factorization.

18821291376543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44363466.

The product of its digits is 17418240, while the sum is 60.

The spelling of 18821291376543 in words is "eighteen trillion, eight hundred twenty-one billion, two hundred ninety-one million, three hundred seventy-six thousand, five hundred forty-three".