78639280440 has 256 divisors, whose sum is σ = 274914432000. Its totient is φ = 17623388160.

The previous prime is 78639280439. The next prime is 78639280453. The reversal of 78639280440 is 4408293687.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 20862876 + ... + 20866644.

It is an arithmetic number, because the mean of its divisors is an integer number (1073884500).

Almost surely, 2^78639280440 is an apocalyptic number.

78639280440 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78639280440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137457216000).

78639280440 is an abundant number, since it is smaller than the sum of its proper divisors (196275151560).

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

78639280440 is a wasteful number, since it uses less digits than its factorization.

78639280440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4270 (or 4266 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 51.

The spelling of 78639280440 in words is "seventy-eight billion, six hundred thirty-nine million, two hundred eighty thousand, four hundred forty".