689645 has 8 divisors (see below), whose sum is σ = 902880. Its totient is φ = 501520.

The previous prime is 689641. The next prime is 689693. The reversal of 689645 is 546986.

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

It is not a de Polignac number, because 689645 - 2² = 689641 is a prime.

It is a super-3 number, since 3×689645³ = 984006642981033375, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 689599 and 689608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689641) 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 7 ways as a sum of consecutive naturals, for example, 6215 + ... + 6324.

It is an arithmetic number, because the mean of its divisors is an integer number (112860).

2⁶⁸⁹⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

689645 is a deficient number, since it is larger than the sum of its proper divisors (213235).

689645 is a wasteful number, since it uses less digits than its factorization.

689645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12555.

The product of its digits is 51840, while the sum is 38.

The square root of 689645 is about 830.4486739107. The cubic root of 689645 is about 88.3504021444.

The spelling of 689645 in words is "six hundred eighty-nine thousand, six hundred forty-five".