19958716243 has 4 divisors (see below), whose sum is σ = 19964689888. Its totient is φ = 19952742600.

The previous prime is 19958716201. The next prime is 19958716259. The reversal of 19958716243 is 34261785991.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19958716243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19958716273) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2981808 + ... + 2988493.

It is an arithmetic number, because the mean of its divisors is an integer number (4991172472).

Almost surely, 2^19958716243 is an apocalyptic number.

19958716243 is a deficient number, since it is larger than the sum of its proper divisors (5973645).

19958716243 is an equidigital number, since it uses as much as digits as its factorization.

19958716243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5973644.

The product of its digits is 3265920, while the sum is 55.

The spelling of 19958716243 in words is "nineteen billion, nine hundred fifty-eight million, seven hundred sixteen thousand, two hundred forty-three".