7778366638540 has 24 divisors (see below), whose sum is σ = 16897830974640. Its totient is φ = 3004058839488.

The previous prime is 7778366638519. The next prime is 7778366638577. The reversal of 7778366638540 is 458366638777.

It is a self number, because there is not a number n which added to its sum of digits gives 7778366638540.

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, 6705487902 + ... + 6705489061.

It is an arithmetic number, because the mean of its divisors is an integer number (704076290610).

Almost surely, 2^{7778366638540} is an apocalyptic number.

It is an amenable number.

7778366638540 is an abundant number, since it is smaller than the sum of its proper divisors (9119464336100).

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

7778366638540 is a wasteful number, since it uses less digits than its factorization.

7778366638540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13410977001 (or 13410976999 counting only the distinct ones).

The product of its (nonzero) digits is 853493760, while the sum is 70.

The spelling of 7778366638540 in words is "seven trillion, seven hundred seventy-eight billion, three hundred sixty-six million, six hundred thirty-eight thousand, five hundred forty".