78857785440 has 768 divisors, whose sum is σ = 338929920000. Its totient is φ = 17069875200.

The previous prime is 78857785439. The next prime is 78857785451. The reversal of 78857785440 is 4458775887.

78857785440 is a `hidden beast` number, since 7 + 8 + 8 + 577 + 8 + 54 + 4 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 28152040 + ... + 28154840.

It is an arithmetic number, because the mean of its divisors is an integer number (441315000).

Almost surely, 2^78857785440 is an apocalyptic number.

78857785440 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 78857785440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169464960000).

78857785440 is an abundant number, since it is smaller than the sum of its proper divisors (260072134560).

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

78857785440 is a wasteful number, since it uses less digits than its factorization.

78857785440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2865 (or 2837 counting only the distinct ones).

The product of its (nonzero) digits is 70246400, while the sum is 63.

The spelling of 78857785440 in words is "seventy-eight billion, eight hundred fifty-seven million, seven hundred eighty-five thousand, four hundred forty".