7720778664 has 48 divisors (see below), whose sum is σ = 20938432320. Its totient is φ = 2570148000.

The previous prime is 7720778627. The next prime is 7720778671. The reversal of 7720778664 is 4668770277.

It is a super-3 number, since 3×7720778664³ (a number of 31 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 7720778664.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17322 + ... + 125465.

It is an arithmetic number, because the mean of its divisors is an integer number (436217340).

Almost surely, 2^7720778664 is an apocalyptic number.

It is an amenable number.

7720778664 is an abundant number, since it is smaller than the sum of its proper divisors (13217653656).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7720778664 is a wasteful number, since it uses less digits than its factorization.

7720778664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143550 (or 143543 counting only the distinct ones).

The product of its (nonzero) digits is 5531904, while the sum is 54.

The square root of 7720778664 is about 87867.9615332005. The cubic root of 7720778664 is about 1976.4554705489.

The spelling of 7720778664 in words is "seven billion, seven hundred twenty million, seven hundred seventy-eight thousand, six hundred sixty-four".