77787278791 has 2 divisors, whose sum is σ = 77787278792. Its totient is φ = 77787278790.

The previous prime is 77787278729. The next prime is 77787278809. The reversal of 77787278791 is 19787278777.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 77787278791 - 2⁹ = 77787278279 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77787278791.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77787278711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38893639395 + 38893639396.

It is an arithmetic number, because the mean of its divisors is an integer number (38893639396).

Almost surely, 2^77787278791 is an apocalyptic number.

77787278791 is a deficient number, since it is larger than the sum of its proper divisors (1).

77787278791 is an equidigital number, since it uses as much as digits as its factorization.

77787278791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 135531648, while the sum is 70.

The spelling of 77787278791 in words is "seventy-seven billion, seven hundred eighty-seven million, two hundred seventy-eight thousand, seven hundred ninety-one".