1978456565632 has 128 divisors (see below), whose sum is σ = 4178998058400. Its totient is φ = 930376212480.

The previous prime is 1978456565621. The next prime is 1978456565671. The reversal of 1978456565632 is 2365656548791.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 848029938 + ... + 848032270.

Almost surely, 2^{1978456565632} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1978456565632, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2089499029200).

1978456565632 is an abundant number, since it is smaller than the sum of its proper divisors (2200541492768).

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

1978456565632 is a wasteful number, since it uses less digits than its factorization.

1978456565632 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4744 (or 4732 counting only the distinct ones).

The product of its digits is 326592000, while the sum is 67.

The spelling of 1978456565632 in words is "one trillion, nine hundred seventy-eight billion, four hundred fifty-six million, five hundred sixty-five thousand, six hundred thirty-two".