78778687787 has 16 divisors (see below), whose sum is σ = 79825374720. Its totient is φ = 77738028672.

The previous prime is 78778687781. The next prime is 78778687913.

78778687787 is nontrivially palindromic in base 10.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78778687787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78778687781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 50726003 + ... + 50727555.

It is an arithmetic number, because the mean of its divisors is an integer number (4989085920).

Almost surely, 2^78778687787 is an apocalyptic number.

78778687787 is a deficient number, since it is larger than the sum of its proper divisors (1046686933).

78778687787 is a wasteful number, since it uses less digits than its factorization.

78778687787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3082.

The product of its digits is 2891341824, while the sum is 80.

The spelling of 78778687787 in words is "seventy-eight billion, seven hundred seventy-eight million, six hundred eighty-seven thousand, seven hundred eighty-seven".