78517 has 2 divisors, whose sum is σ = 78518. Its totient is φ = 78516.

The previous prime is 78511. The next prime is 78539. The reversal of 78517 is 71587.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77841 + 676 = 279^2 + 26^2 .

It is a cyclic number.

It is not a de Polignac number, because 78517 - 2³ = 78509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39258 + 39259.

It is an arithmetic number, because the mean of its divisors is an integer number (39259).

2⁷⁸⁵¹⁷ is an apocalyptic number.

It is an amenable number.

78517 is a deficient number, since it is larger than the sum of its proper divisors (1).

78517 is an equidigital number, since it uses as much as digits as its factorization.

78517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1960, while the sum is 28.

The square root of 78517 is about 280.2088506811. The cubic root of 78517 is about 42.8207792076.

It can be divided in two parts, 78 and 517, that added together give a palindrome (595).

The spelling of 78517 in words is "seventy-eight thousand, five hundred seventeen".