78728439 has 8 divisors (see below), whose sum is σ = 105046272. Its totient is φ = 52448120.

The previous prime is 78728423. The next prime is 78728483. The reversal of 78728439 is 93482787.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 78728439 - 2⁴ = 78728423 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78728339) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4047 + ... + 13184.

It is an arithmetic number, because the mean of its divisors is an integer number (13130784).

Almost surely, 2^78728439 is an apocalyptic number.

78728439 is a deficient number, since it is larger than the sum of its proper divisors (26317833).

78728439 is a wasteful number, since it uses less digits than its factorization.

78728439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18757.

The product of its digits is 677376, while the sum is 48.

The square root of 78728439 is about 8872.9047667604. The cubic root of 78728439 is about 428.5918221883.

The spelling of 78728439 in words is "seventy-eight million, seven hundred twenty-eight thousand, four hundred thirty-nine".