78658947664 has 80 divisors (see below), whose sum is σ = 170978610240. Its totient is φ = 34751175680.

The previous prime is 78658947643. The next prime is 78658947673. The reversal of 78658947664 is 46674985687.

It is a junction number, because it is equal to n+sod(n) for n = 78658947593 and 78658947602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 958692 + ... + 1037500.

It is an arithmetic number, because the mean of its divisors is an integer number (2137232628).

Almost surely, 2^78658947664 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 78658947664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85489305120).

78658947664 is an abundant number, since it is smaller than the sum of its proper divisors (92319662576).

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

78658947664 is a wasteful number, since it uses less digits than its factorization.

78658947664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78988 (or 78982 counting only the distinct ones).

The product of its digits is 487710720, while the sum is 70.

The spelling of 78658947664 in words is "seventy-eight billion, six hundred fifty-eight million, nine hundred forty-seven thousand, six hundred sixty-four".