689686809 has 24 divisors (see below), whose sum is σ = 1116233280. Its totient is φ = 376969824.

The previous prime is 689686769. The next prime is 689686861. The reversal of 689686809 is 908686986.

It is not a de Polignac number, because 689686809 - 2¹¹ = 689684761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (689646809) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 98614 + ... + 105375.

It is an arithmetic number, because the mean of its divisors is an integer number (46509720).

Almost surely, 2^689686809 is an apocalyptic number.

689686809 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

It is an amenable number.

689686809 is a deficient number, since it is larger than the sum of its proper divisors (426546471).

689686809 is a wasteful number, since it uses less digits than its factorization.

689686809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204029 (or 204022 counting only the distinct ones).

The product of its (nonzero) digits is 8957952, while the sum is 60.

The square root of 689686809 is about 26261.8889076928. Note that the first 3 decimals coincide. The cubic root of 689686809 is about 883.5218749158.

The spelling of 689686809 in words is "six hundred eighty-nine million, six hundred eighty-six thousand, eight hundred nine".