78770885777 has 2 divisors, whose sum is σ = 78770885778. Its totient is φ = 78770885776.

The previous prime is 78770885749. The next prime is 78770885813. The reversal of 78770885777 is 77758807787.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 72574204816 + 6196680961 = 269396^2 + 78719^2 .

It is an emirp because it is prime and its reverse (77758807787) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78770885777 - 2⁸ = 78770885521 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78770885777.

It is not a weakly prime, because it can be changed into another prime (78770885707) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39385442888 + 39385442889.

It is an arithmetic number, because the mean of its divisors is an integer number (39385442889).

Almost surely, 2^78770885777 is an apocalyptic number.

It is an amenable number.

78770885777 is a deficient number, since it is larger than the sum of its proper divisors (1).

78770885777 is an equidigital number, since it uses as much as digits as its factorization.

78770885777 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 301181440, while the sum is 71.

The spelling of 78770885777 in words is "seventy-eight billion, seven hundred seventy million, eight hundred eighty-five thousand, seven hundred seventy-seven".