78430657 has 2 divisors, whose sum is σ = 78430658. Its totient is φ = 78430656.

The previous prime is 78430643. The next prime is 78430687. The reversal of 78430657 is 75603487.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 60078001 + 18352656 = 7751^2 + 4284^2 .

It is an emirp because it is prime and its reverse (75603487) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78430657 - 2¹⁵ = 78397889 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78430607) 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 as a sum of consecutive naturals, namely, 39215328 + 39215329.

It is an arithmetic number, because the mean of its divisors is an integer number (39215329).

Almost surely, 2^78430657 is an apocalyptic number.

It is an amenable number.

78430657 is a deficient number, since it is larger than the sum of its proper divisors (1).

78430657 is an equidigital number, since it uses as much as digits as its factorization.

78430657 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 141120, while the sum is 40.

The square root of 78430657 is about 8856.1084568788. The cubic root of 78430657 is about 428.0507717013.

The spelling of 78430657 in words is "seventy-eight million, four hundred thirty thousand, six hundred fifty-seven".