78817320 has 256 divisors, whose sum is σ = 290304000. Its totient is φ = 18931968.

The previous prime is 78817267. The next prime is 78817337. The reversal of 78817320 is 2371887.

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 63 ways as a sum of consecutive naturals, for example, 471877 + ... + 472043.

It is an arithmetic number, because the mean of its divisors is an integer number (1134000).

Almost surely, 2^78817320 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78817320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145152000).

78817320 is an abundant number, since it is smaller than the sum of its proper divisors (211486680).

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

78817320 is a wasteful number, since it uses less digits than its factorization.

78817320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 78817320 is about 8877.9119166615. The cubic root of 78817320 is about 428.7530487363.

The spelling of 78817320 in words is "seventy-eight million, eight hundred seventeen thousand, three hundred twenty".