77779997777 has 2 divisors, whose sum is σ = 77779997778. Its totient is φ = 77779997776.

The previous prime is 77779997753. The next prime is 77779997819.

It is a happy number.

77779997777 is nontrivially palindromic in base 10.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68937228481 + 8842769296 = 262559^2 + 94036^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 77779997777 - 2¹⁴ = 77779981393 is a prime.

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 77779997695 and 77779997704.

It is not a weakly prime, because it can be changed into another prime (77779997077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38889998888 + 38889998889.

It is an arithmetic number, because the mean of its divisors is an integer number (38889998889).

Almost surely, 2^77779997777 is an apocalyptic number.

It is an amenable number.

77779997777 is a deficient number, since it is larger than the sum of its proper divisors (1).

77779997777 is an equidigital number, since it uses as much as digits as its factorization.

77779997777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4202539929, while the sum is 83.

The spelling of 77779997777 in words is "seventy-seven billion, seven hundred seventy-nine million, nine hundred ninety-seven thousand, seven hundred seventy-seven".