13781856449 has 2 divisors, whose sum is σ = 13781856450. Its totient is φ = 13781856448.

The previous prime is 13781856443. The next prime is 13781856467. The reversal of 13781856449 is 94465818731.

It is a happy number.

13781856449 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13656259600 + 125596849 = 116860^2 + 11207^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13781856449 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13781856394 and 13781856403.

It is not a weakly prime, because it can be changed into another prime (13781856443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6890928224 + 6890928225.

It is an arithmetic number, because the mean of its divisors is an integer number (6890928225).

Almost surely, 2^13781856449 is an apocalyptic number.

It is an amenable number.

13781856449 is a deficient number, since it is larger than the sum of its proper divisors (1).

13781856449 is an equidigital number, since it uses as much as digits as its factorization.

13781856449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5806080, while the sum is 56.

The spelling of 13781856449 in words is "thirteen billion, seven hundred eighty-one million, eight hundred fifty-six thousand, four hundred forty-nine".