1863781067549 has 2 divisors, whose sum is σ = 1863781067550. Its totient is φ = 1863781067548.

The previous prime is 1863781067537. The next prime is 1863781067567. The reversal of 1863781067549 is 9457601873681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1486004884324 + 377776183225 = 1219018^2 + 614635^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1863781067549 is a prime.

It is a super-3 number, since 3×1863781067549³ (a number of 38 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1863781060549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 931890533774 + 931890533775.

It is an arithmetic number, because the mean of its divisors is an integer number (931890533775).

Almost surely, 2^{1863781067549} is an apocalyptic number.

It is an amenable number.

1863781067549 is a deficient number, since it is larger than the sum of its proper divisors (1).

1863781067549 is an equidigital number, since it uses as much as digits as its factorization.

1863781067549 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60963840, while the sum is 65.

The spelling of 1863781067549 in words is "one trillion, eight hundred sixty-three billion, seven hundred eighty-one million, sixty-seven thousand, five hundred forty-nine".