7788777778877 has 2 divisors, whose sum is σ = 7788777778878. Its totient is φ = 7788777778876.

The previous prime is 7788777778841. The next prime is 7788777778897.

7788777778877 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4318329207481 + 3470448571396 = 2078059^2 + 1862914^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 7788777778877 - 2²⁸ = 7788509343421 is a prime.

It is a super-2 number, since 2×7788777778877² (a number of 27 digits) contains 22 as substring.

It is a zygodrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 7788777778877.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7788777778897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3894388889438 + 3894388889439.

It is an arithmetic number, because the mean of its divisors is an integer number (3894388889439).

Almost surely, 2^{7788777778877} is an apocalyptic number.

It is an amenable number.

7788777778877 is a deficient number, since it is larger than the sum of its proper divisors (1).

7788777778877 is an equidigital number, since it uses as much as digits as its factorization.

7788777778877 is an evil number, because the sum of its binary digits is even.

The product of its digits is 165288374272, while the sum is 95.

The spelling of 7788777778877 in words is "seven trillion, seven hundred eighty-eight billion, seven hundred seventy-seven million, seven hundred seventy-eight thousand, eight hundred seventy-seven".