1916803329781 has 2 divisors, whose sum is σ = 1916803329782. Its totient is φ = 1916803329780.

The previous prime is 1916803329769. The next prime is 1916803329809. The reversal of 1916803329781 is 1879233086191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1481658610756 + 435144719025 = 1217234^2 + 659655^2 .

It is an emirp because it is prime and its reverse (1879233086191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1916803329781 - 2³¹ = 1914655846133 is a prime.

It is a super-2 number, since 2×1916803329781² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1916803320781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 958401664890 + 958401664891.

It is an arithmetic number, because the mean of its divisors is an integer number (958401664891).

Almost surely, 2^{1916803329781} is an apocalyptic number.

It is an amenable number.

1916803329781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1916803329781 is an equidigital number, since it uses as much as digits as its factorization.

1916803329781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3919104, while the sum is 58.

The spelling of 1916803329781 in words is "one trillion, nine hundred sixteen billion, eight hundred three million, three hundred twenty-nine thousand, seven hundred eighty-one".