78704640 has 312 divisors, whose sum is σ = 316893408. Its totient is φ = 17694720.

The previous prime is 78704623. The next prime is 78704677. The reversal of 78704640 is 4640787.

It is a happy number.

78704640 is a `hidden beast` number, since 7 + 8 + 7 + 0 + 4 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 78704595 and 78704604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1290210 + ... + 1290270.

It is an arithmetic number, because the mean of its divisors is an integer number (1015684).

Almost surely, 2^78704640 is an apocalyptic number.

78704640 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 78704640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158446704).

78704640 is an abundant number, since it is smaller than the sum of its proper divisors (238188768).

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

78704640 is a wasteful number, since it uses less digits than its factorization.

78704640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 78704640 is about 8871.5635600496. The cubic root of 78704640 is about 428.5486311683.

The spelling of 78704640 in words is "seventy-eight million, seven hundred four thousand, six hundred forty".