1778318661664 has 24 divisors (see below), whose sum is σ = 3509039983680. Its totient is φ = 887133903936.

The previous prime is 1778318661607. The next prime is 1778318661667. The reversal of 1778318661664 is 4661668138771.

It is a junction number, because it is equal to n+sod(n) for n = 1778318661596 and 1778318661605.

It is not an unprimeable number, because it can be changed into a prime (1778318661667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63280324 + ... + 63308419.

It is an arithmetic number, because the mean of its divisors is an integer number (146209999320).

Almost surely, 2^{1778318661664} is an apocalyptic number.

It is an amenable number.

1778318661664 is a deficient number, since it is larger than the sum of its proper divisors (1730721322016).

1778318661664 is a wasteful number, since it uses less digits than its factorization.

1778318661664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126589192 (or 126589184 counting only the distinct ones).

The product of its digits is 48771072, while the sum is 64.

The spelling of 1778318661664 in words is "one trillion, seven hundred seventy-eight billion, three hundred eighteen million, six hundred sixty-one thousand, six hundred sixty-four".