78425309 has 16 divisors (see below), whose sum is σ = 83166720. Its totient is φ = 73846080.

The previous prime is 78425261. The next prime is 78425317. The reversal of 78425309 is 90352487.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78425309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78425339) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 351572 + ... + 351794.

It is an arithmetic number, because the mean of its divisors is an integer number (5197920).

Almost surely, 2^78425309 is an apocalyptic number.

It is an amenable number.

78425309 is a deficient number, since it is larger than the sum of its proper divisors (4741411).

78425309 is a wasteful number, since it uses less digits than its factorization.

78425309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500.

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 78425309 is about 8855.8065132432. The cubic root of 78425309 is about 428.0410422254.

The spelling of 78425309 in words is "seventy-eight million, four hundred twenty-five thousand, three hundred nine".