78820320 has 48 divisors (see below), whose sum is σ = 248285520. Its totient is φ = 21018624.

The previous prime is 78820319. The next prime is 78820331. The reversal of 78820320 is 2302887.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (30).

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 7 ways as a sum of consecutive naturals, for example, 81625 + ... + 82584.

It is an arithmetic number, because the mean of its divisors is an integer number (5172615).

Almost surely, 2^78820320 is an apocalyptic number.

It is an amenable number.

78820320 is an abundant number, since it is smaller than the sum of its proper divisors (169465200).

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

78820320 is a wasteful number, since it uses less digits than its factorization.

78820320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164227 (or 164219 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 30.

The square root of 78820320 is about 8878.0808737024. The cubic root of 78820320 is about 428.7584885002.

Subtracting from 78820320 its sum of digits (30), we obtain a triangular number (78820290 = T₁₂₅₅₅).

The spelling of 78820320 in words is "seventy-eight million, eight hundred twenty thousand, three hundred twenty".