19813247989 has 2 divisors, whose sum is σ = 19813247990. Its totient is φ = 19813247988.

The previous prime is 19813247977. The next prime is 19813248019. The reversal of 19813247989 is 98974231891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14780480625 + 5032767364 = 121575^2 + 70942^2 .

It is an emirp because it is prime and its reverse (98974231891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19813247989 - 2²¹ = 19811150837 is a prime.

It is a super-3 number, since 3×19813247989³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19813247189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9906623994 + 9906623995.

It is an arithmetic number, because the mean of its divisors is an integer number (9906623995).

Almost surely, 2^19813247989 is an apocalyptic number.

It is an amenable number.

19813247989 is a deficient number, since it is larger than the sum of its proper divisors (1).

19813247989 is an equidigital number, since it uses as much as digits as its factorization.

19813247989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7838208, while the sum is 61.

The spelling of 19813247989 in words is "nineteen billion, eight hundred thirteen million, two hundred forty-seven thousand, nine hundred eighty-nine".