689729 has 4 divisors (see below), whose sum is σ = 696660. Its totient is φ = 682800.

The previous prime is 689723. The next prime is 689761. The reversal of 689729 is 927986.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 927986 = 2 ⋅463993.

It can be written as a sum of positive squares in 2 ways, for example, as 547600 + 142129 = 740^2 + 377^2 .

It is a cyclic number.

It is not a de Polignac number, because 689729 - 2⁴ = 689713 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (689723) 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 3 ways as a sum of consecutive naturals, for example, 3314 + ... + 3515.

It is an arithmetic number, because the mean of its divisors is an integer number (174165).

2⁶⁸⁹⁷²⁹ is an apocalyptic number.

It is an amenable number.

689729 is a deficient number, since it is larger than the sum of its proper divisors (6931).

689729 is a wasteful number, since it uses less digits than its factorization.

689729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6930.

The product of its digits is 54432, while the sum is 41.

The square root of 689729 is about 830.4992474410. The cubic root of 689729 is about 88.3539890780.

The spelling of 689729 in words is "six hundred eighty-nine thousand, seven hundred twenty-nine".