8128839978 has 96 divisors (see below), whose sum is σ = 20500107264. Its totient is φ = 2280047616.

The previous prime is 8128839941. The next prime is 8128839989. The reversal of 8128839978 is 8799388218.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1549576 + ... + 1554812.

It is an arithmetic number, because the mean of its divisors is an integer number (213542784).

Almost surely, 2^8128839978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8128839978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10250053632).

8128839978 is an abundant number, since it is smaller than the sum of its proper divisors (12371267286).

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

8128839978 is a wasteful number, since it uses less digits than its factorization.

8128839978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5476 (or 5473 counting only the distinct ones).

The product of its digits is 13934592, while the sum is 63.

The square root of 8128839978 is about 90160.0797359896. The cubic root of 8128839978 is about 2010.6795370749.

The spelling of 8128839978 in words is "eight billion, one hundred twenty-eight million, eight hundred thirty-nine thousand, nine hundred seventy-eight".