77777788777778 has 16 divisors (see below), whose sum is σ = 116803978331040. Its totient is φ = 38843130238176.

The previous prime is 77777788777739. The next prime is 77777788777789. The reversal of 77777788777778 is 87777788777777.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 259245125 + ... + 259544967.

It is an arithmetic number, because the mean of its divisors is an integer number (7300248645690).

Almost surely, 2^{77777788777778} is an apocalyptic number.

77777788777778 is a deficient number, since it is larger than the sum of its proper divisors (39026189553262).

77777788777778 is a wasteful number, since it uses less digits than its factorization.

77777788777778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452041.

The product of its digits is 1012391292416, while the sum is 101.

Subtracting 77777788777778 from its reverse (87777788777777), we obtain a palindrome (9999999999999).

The spelling of 77777788777778 in words is "seventy-seven trillion, seven hundred seventy-seven billion, seven hundred eighty-eight million, seven hundred seventy-seven thousand, seven hundred seventy-eight".