7718778064 has 20 divisors (see below), whose sum is σ = 15165770400. Its totient is φ = 3805030880.

The previous prime is 7718778059. The next prime is 7718778077. The reversal of 7718778064 is 4608778177.

It is a junction number, because it is equal to n+sod(n) for n = 7718777996 and 7718778014.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3396214 + ... + 3398485.

It is an arithmetic number, because the mean of its divisors is an integer number (758288520).

Almost surely, 2^7718778064 is an apocalyptic number.

It is an amenable number.

7718778064 is a deficient number, since it is larger than the sum of its proper divisors (7446992336).

7718778064 is a wasteful number, since it uses less digits than its factorization.

7718778064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6794778 (or 6794772 counting only the distinct ones).

The product of its (nonzero) digits is 3687936, while the sum is 55.

The square root of 7718778064 is about 87856.5766690235. The cubic root of 7718778064 is about 1976.2847434516.

The spelling of 7718778064 in words is "seven billion, seven hundred eighteen million, seven hundred seventy-eight thousand, sixty-four".