78446784640 has 256 divisors, whose sum is σ = 223351603200. Its totient is φ = 25780285440.

The previous prime is 78446784613. The next prime is 78446784649. The reversal of 78446784640 is 4648764487.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (78446784649) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14857521 + ... + 14862799.

It is an arithmetic number, because the mean of its divisors is an integer number (872467200).

Almost surely, 2^78446784640 is an apocalyptic number.

78446784640 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 78446784640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111675801600).

78446784640 is an abundant number, since it is smaller than the sum of its proper divisors (144904818560).

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

78446784640 is a wasteful number, since it uses less digits than its factorization.

78446784640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5443 (or 5431 counting only the distinct ones).

The product of its (nonzero) digits is 28901376, while the sum is 58.

The spelling of 78446784640 in words is "seventy-eight billion, four hundred forty-six million, seven hundred eighty-four thousand, six hundred forty".