19785239781269 has 2 divisors, whose sum is σ = 19785239781270. Its totient is φ = 19785239781268.

The previous prime is 19785239781259. The next prime is 19785239781313. The reversal of 19785239781269 is 96218793258791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12803966097169 + 6981273684100 = 3578263^2 + 2642210^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19785239781269 is a prime.

It is a super-2 number, since 2×19785239781269² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19785239781269.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19785239781259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9892619890634 + 9892619890635.

It is an arithmetic number, because the mean of its divisors is an integer number (9892619890635).

Almost surely, 2^{19785239781269} is an apocalyptic number.

It is an amenable number.

19785239781269 is a deficient number, since it is larger than the sum of its proper divisors (1).

19785239781269 is an equidigital number, since it uses as much as digits as its factorization.

19785239781269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 823011840, while the sum is 77.

The spelling of 19785239781269 in words is "nineteen trillion, seven hundred eighty-five billion, two hundred thirty-nine million, seven hundred eighty-one thousand, two hundred sixty-nine".