678617 has 4 divisors (see below), whose sum is σ = 696996. Its totient is φ = 660240.

The previous prime is 678611. The next prime is 678631. The reversal of 678617 is 716876.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 337561 + 341056 = 581^2 + 584^2 .

It is a cyclic number.

It is not a de Polignac number, because 678617 - 2⁶ = 678553 is a prime.

It is a super-3 number, since 3×678617³ = 937552204920933339, which contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (678611) 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 in 3 ways as a sum of consecutive naturals, for example, 9134 + ... + 9207.

It is an arithmetic number, because the mean of its divisors is an integer number (174249).

2⁶⁷⁸⁶¹⁷ is an apocalyptic number.

It is an amenable number.

678617 is a deficient number, since it is larger than the sum of its proper divisors (18379).

678617 is a wasteful number, since it uses less digits than its factorization.

678617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18378.

The product of its digits is 14112, while the sum is 35.

The square root of 678617 is about 823.7821313915. The cubic root of 678617 is about 87.8769371438.

The spelling of 678617 in words is "six hundred seventy-eight thousand, six hundred seventeen".