78535718168581 has 2 divisors, whose sum is σ = 78535718168582. Its totient is φ = 78535718168580.

The previous prime is 78535718168549. The next prime is 78535718168587. The reversal of 78535718168581 is 18586181753587.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48364152260356 + 30171565908225 = 6954434^2 + 5492865^2 .

It is a cyclic number.

It is not a de Polignac number, because 78535718168581 - 2⁵ = 78535718168549 is a prime.

It is a super-2 number, since 2×78535718168581² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78535718168587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39267859084290 + 39267859084291.

It is an arithmetic number, because the mean of its divisors is an integer number (39267859084291).

Almost surely, 2^{78535718168581} is an apocalyptic number.

It is an amenable number.

78535718168581 is a deficient number, since it is larger than the sum of its proper divisors (1).

78535718168581 is an equidigital number, since it uses as much as digits as its factorization.

78535718168581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 451584000, while the sum is 73.

The spelling of 78535718168581 in words is "seventy-eight trillion, five hundred thirty-five billion, seven hundred eighteen million, one hundred sixty-eight thousand, five hundred eighty-one".