78407240 has 32 divisors (see below), whose sum is σ = 176715000. Its totient is φ = 31309824.

The previous prime is 78407239. The next prime is 78407249. The reversal of 78407240 is 4270487.

It can be written as a sum of positive squares in 4 ways, for example, as 73034116 + 5373124 = 8546^2 + 2318^2 .

It is a super-2 number, since 2×78407240² = 12295390568835200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 78407197 and 78407206.

It is not an unprimeable number, because it can be changed into a prime (78407249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29486 + ... + 32034.

Almost surely, 2^78407240 is an apocalyptic number.

It is an amenable number.

78407240 is an abundant number, since it is smaller than the sum of its proper divisors (98307760).

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

78407240 is a wasteful number, since it uses less digits than its factorization.

78407240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3329 (or 3325 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 32.

The square root of 78407240 is about 8854.7862763592. The cubic root of 78407240 is about 428.0081664963.

The spelling of 78407240 in words is "seventy-eight million, four hundred seven thousand, two hundred forty".