689999 has 4 divisors (see below), whose sum is σ = 693000. Its totient is φ = 687000.

The previous prime is 689987. The next prime is 690037. The reversal of 689999 is 999986.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-689999 is a prime.

It is a Duffinian number.

689999 is a modest number, since divided by 999 gives 689 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 689999.

It is not an unprimeable number, because it can be changed into a prime (689929) 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, 1124 + ... + 1625.

It is an arithmetic number, because the mean of its divisors is an integer number (173250).

2⁶⁸⁹⁹⁹⁹ is an apocalyptic number.

689999 is a deficient number, since it is larger than the sum of its proper divisors (3001).

689999 is a wasteful number, since it uses less digits than its factorization.

689999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3000.

The product of its digits is 314928, while the sum is 50.

The square root of 689999 is about 830.6617843623. The cubic root of 689999 is about 88.3655165353.

The spelling of 689999 in words is "six hundred eighty-nine thousand, nine hundred ninety-nine".