1081518355781 has 2 divisors, whose sum is σ = 1081518355782. Its totient is φ = 1081518355780.

The previous prime is 1081518355769. The next prime is 1081518355783. The reversal of 1081518355781 is 1875538151801.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1045649404900 + 35868950881 = 1022570^2 + 189391^2 .

It is a cyclic number.

It is not a de Polignac number, because 1081518355781 - 2³⁰ = 1080444613957 is a prime.

It is a super-2 number, since 2×1081518355781² (a number of 25 digits) contains 22 as substring.

Together with 1081518355783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1081518355783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 540759177890 + 540759177891.

It is an arithmetic number, because the mean of its divisors is an integer number (540759177891).

Almost surely, 2^{1081518355781} is an apocalyptic number.

It is an amenable number.

1081518355781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1081518355781 is an equidigital number, since it uses as much as digits as its factorization.

1081518355781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1344000, while the sum is 53.

The spelling of 1081518355781 in words is "one trillion, eighty-one billion, five hundred eighteen million, three hundred fifty-five thousand, seven hundred eighty-one".