68778441980581 has 2 divisors, whose sum is σ = 68778441980582. Its totient is φ = 68778441980580.

The previous prime is 68778441980561. The next prime is 68778441980593. The reversal of 68778441980581 is 18508914487786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66439469383681 + 2338972596900 = 8151041^2 + 1529370^2 .

It is a cyclic number.

It is not a de Polignac number, because 68778441980581 - 2²⁵ = 68778408426149 is a prime.

It is a super-2 number, since 2×68778441980581² (a number of 28 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 68778441980498 and 68778441980507.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68778441980561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34389220990290 + 34389220990291.

It is an arithmetic number, because the mean of its divisors is an integer number (34389220990291).

Almost surely, 2^{68778441980581} is an apocalyptic number.

It is an amenable number.

68778441980581 is a deficient number, since it is larger than the sum of its proper divisors (1).

68778441980581 is an equidigital number, since it uses as much as digits as its factorization.

68778441980581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 867041280, while the sum is 76.

The spelling of 68778441980581 in words is "sixty-eight trillion, seven hundred seventy-eight billion, four hundred forty-one million, nine hundred eighty thousand, five hundred eighty-one".