78217 has 8 divisors (see below), whose sum is σ = 85536. Its totient is φ = 71232.

The previous prime is 78203. The next prime is 78229. The reversal of 78217 is 71287.

It is a happy number.

78217 is nontrivially palindromic in base 6.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78217 is a prime.

It is a super-2 number, since 2×78217² = 12235798178, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78191 and 78200.

It is not an unprimeable number, because it can be changed into a prime (78277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 678 + ... + 784.

It is an arithmetic number, because the mean of its divisors is an integer number (10692).

2⁷⁸²¹⁷ is an apocalyptic number.

It is an amenable number.

78217 is a deficient number, since it is larger than the sum of its proper divisors (7319).

78217 is a wasteful number, since it uses less digits than its factorization.

78217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167.

The product of its digits is 784, while the sum is 25.

The square root of 78217 is about 279.6730233684. The cubic root of 78217 is about 42.7661726482.

The spelling of 78217 in words is "seventy-eight thousand, two hundred seventeen".