19785239781313 has 2 divisors, whose sum is σ = 19785239781314. Its totient is φ = 19785239781312.

The previous prime is 19785239781269. The next prime is 19785239781331. The reversal of 19785239781313 is 31318793258791.

Together with next prime (19785239781331) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11508703432704 + 8276536348609 = 3392448^2 + 2876897^2 .

It is a cyclic number.

It is not a de Polignac number, because 19785239781313 - 2³³ = 19776649846721 is a prime.

It is not a weakly prime, because it can be changed into another prime (19785239781353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9892619890656 + 9892619890657.

It is an arithmetic number, because the mean of its divisors is an integer number (9892619890657).

Almost surely, 2^{19785239781313} is an apocalyptic number.

It is an amenable number.

19785239781313 is a deficient number, since it is larger than the sum of its proper divisors (1).

19785239781313 is an equidigital number, since it uses as much as digits as its factorization.

19785239781313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 68584320, while the sum is 67.

The spelling of 19785239781313 in words is "nineteen trillion, seven hundred eighty-five billion, two hundred thirty-nine million, seven hundred eighty-one thousand, three hundred thirteen".