78309320 has 32 divisors (see below), whose sum is σ = 178183800. Its totient is φ = 30970368.

The previous prime is 78309307. The next prime is 78309347. The reversal of 78309320 is 2390387.

It can be written as a sum of positive squares in 4 ways, for example, as 56761156 + 21548164 = 7534^2 + 4642^2 .

It is a super-2 number, since 2×78309320² = 12264699197724800, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7439 + ... + 14558.

Almost surely, 2^78309320 is an apocalyptic number.

It is an amenable number.

78309320 is an abundant number, since it is smaller than the sum of its proper divisors (99874480).

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

78309320 is a wasteful number, since it uses less digits than its factorization.

78309320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22097 (or 22093 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 78309320 is about 8849.2553359026. The cubic root of 78309320 is about 427.8299175716.

The spelling of 78309320 in words is "seventy-eight million, three hundred nine thousand, three hundred twenty".