78558286561 has 2 divisors, whose sum is σ = 78558286562. Its totient is φ = 78558286560.

The previous prime is 78558286537. The next prime is 78558286591. The reversal of 78558286561 is 16568285587.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78543425536 + 14861025 = 280256^2 + 3855^2 .

It is a cyclic number.

It is not a de Polignac number, because 78558286561 - 2¹¹ = 78558284513 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78558286561.

It is not a weakly prime, because it can be changed into another prime (78558286591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39279143280 + 39279143281.

It is an arithmetic number, because the mean of its divisors is an integer number (39279143281).

Almost surely, 2^78558286561 is an apocalyptic number.

It is an amenable number.

78558286561 is a deficient number, since it is larger than the sum of its proper divisors (1).

78558286561 is an equidigital number, since it uses as much as digits as its factorization.

78558286561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256000, while the sum is 61.

The spelling of 78558286561 in words is "seventy-eight billion, five hundred fifty-eight million, two hundred eighty-six thousand, five hundred sixty-one".