78664320 has 192 divisors, whose sum is σ = 310602240. Its totient is φ = 17971200.

The previous prime is 78664307. The next prime is 78664337. The reversal of 78664320 is 2346687.

78664320 is a `hidden beast` number, since 7 + 8 + 6 + 643 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

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

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, 39345 + ... + 41295.

It is an arithmetic number, because the mean of its divisors is an integer number (1617720).

Almost surely, 2^78664320 is an apocalyptic number.

78664320 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 78664320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155301120).

78664320 is an abundant number, since it is smaller than the sum of its proper divisors (231937920).

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

78664320 is a wasteful number, since it uses less digits than its factorization.

78664320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1983 (or 1968 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 78664320 is about 8869.2908397459. The cubic root of 78664320 is about 428.4754375492.

The spelling of 78664320 in words is "seventy-eight million, six hundred sixty-four thousand, three hundred twenty".