689108639 has 4 divisors (see below), whose sum is σ = 693498024. Its totient is φ = 684719256.

The previous prime is 689108593. The next prime is 689108659. The reversal of 689108639 is 936801986.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936801986 = 2 ⋅468400993.

It is a cyclic number.

It is not a de Polignac number, because 689108639 - 2¹² = 689104543 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689108659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2194457 + ... + 2194770.

It is an arithmetic number, because the mean of its divisors is an integer number (173374506).

Almost surely, 2^689108639 is an apocalyptic number.

689108639 is a deficient number, since it is larger than the sum of its proper divisors (4389385).

689108639 is a wasteful number, since it uses less digits than its factorization.

689108639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4389384.

The product of its (nonzero) digits is 559872, while the sum is 50.

The square root of 689108639 is about 26250.8788233842. The cubic root of 689108639 is about 883.2749180626.

The spelling of 689108639 in words is "six hundred eighty-nine million, one hundred eight thousand, six hundred thirty-nine".