19813764365917 has 2 divisors, whose sum is σ = 19813764365918. Its totient is φ = 19813764365916.

The previous prime is 19813764365903. The next prime is 19813764365947. The reversal of 19813764365917 is 71956346731891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13077813738276 + 6735950627641 = 3616326^2 + 2595371^2 .

It is an emirp because it is prime and its reverse (71956346731891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19813764365917 - 2¹⁹ = 19813763841629 is a prime.

It is a super-3 number, since 3×19813764365917³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19813764365947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9906882182958 + 9906882182959.

It is an arithmetic number, because the mean of its divisors is an integer number (9906882182959).

Almost surely, 2^{19813764365917} is an apocalyptic number.

It is an amenable number.

19813764365917 is a deficient number, since it is larger than the sum of its proper divisors (1).

19813764365917 is an equidigital number, since it uses as much as digits as its factorization.

19813764365917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 205752960, while the sum is 70.

The spelling of 19813764365917 in words is "nineteen trillion, eight hundred thirteen billion, seven hundred sixty-four million, three hundred sixty-five thousand, nine hundred seventeen".