5640055660781 has 2 divisors, whose sum is σ = 5640055660782. Its totient is φ = 5640055660780.

The previous prime is 5640055660721. The next prime is 5640055660807. The reversal of 5640055660781 is 1870665500465.

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., 3642734874025 + 1997320786756 = 1908595^2 + 1413266^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5640055660781 is a prime.

It is a super-2 number, since 2×5640055660781² (a number of 26 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5640055660721) 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, 2820027830390 + 2820027830391.

It is an arithmetic number, because the mean of its divisors is an integer number (2820027830391).

Almost surely, 2^{5640055660781} is an apocalyptic number.

It is an amenable number.

5640055660781 is a deficient number, since it is larger than the sum of its proper divisors (1).

5640055660781 is an equidigital number, since it uses as much as digits as its factorization.

5640055660781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048000, while the sum is 53.

The spelling of 5640055660781 in words is "five trillion, six hundred forty billion, fifty-five million, six hundred sixty thousand, seven hundred eighty-one".