19979218543 has 2 divisors, whose sum is σ = 19979218544. Its totient is φ = 19979218542.

The previous prime is 19979218537. The next prime is 19979218577. The reversal of 19979218543 is 34581297991.

It is a weak prime.

It is an emirp because it is prime and its reverse (34581297991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19979218543 - 2¹³ = 19979210351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19979218243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9989609271 + 9989609272.

It is an arithmetic number, because the mean of its divisors is an integer number (9989609272).

Almost surely, 2^19979218543 is an apocalyptic number.

19979218543 is a deficient number, since it is larger than the sum of its proper divisors (1).

19979218543 is an equidigital number, since it uses as much as digits as its factorization.

19979218543 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4898880, while the sum is 58.

The spelling of 19979218543 in words is "nineteen billion, nine hundred seventy-nine million, two hundred eighteen thousand, five hundred forty-three".