1978218756768 has 48 divisors (see below), whose sum is σ = 5466130780320. Its totient is φ = 624700659456.

The previous prime is 1978218756751. The next prime is 1978218756769. The reversal of 1978218756768 is 8676578128791.

It is a tau number, because it is divible by the number of its divisors (48).

It is a self number, because there is not a number n which added to its sum of digits gives 1978218756768.

It is not an unprimeable number, because it can be changed into a prime (1978218756769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 542273055 + ... + 542276702.

It is an arithmetic number, because the mean of its divisors is an integer number (113877724590).

Almost surely, 2^{1978218756768} is an apocalyptic number.

It is an amenable number.

1978218756768 is an abundant number, since it is smaller than the sum of its proper divisors (3487912023552).

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

1978218756768 is a wasteful number, since it uses less digits than its factorization.

1978218756768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1084549789 (or 1084549781 counting only the distinct ones).

The product of its digits is 568995840, while the sum is 75.

The spelling of 1978218756768 in words is "one trillion, nine hundred seventy-eight billion, two hundred eighteen million, seven hundred fifty-six thousand, seven hundred sixty-eight".