78428587 has 2 divisors, whose sum is σ = 78428588. Its totient is φ = 78428586.

The previous prime is 78428579. The next prime is 78428617. The reversal of 78428587 is 78582487.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78428587 - 2³ = 78428579 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 78428587.

It is not a weakly prime, because it can be changed into another prime (78428887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39214293 + 39214294.

It is an arithmetic number, because the mean of its divisors is an integer number (39214294).

Almost surely, 2^78428587 is an apocalyptic number.

78428587 is a deficient number, since it is larger than the sum of its proper divisors (1).

78428587 is an equidigital number, since it uses as much as digits as its factorization.

78428587 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1003520, while the sum is 49.

The square root of 78428587 is about 8855.9915876202. The cubic root of 78428587 is about 428.0470058572.

The spelling of 78428587 in words is "seventy-eight million, four hundred twenty-eight thousand, five hundred eighty-seven".