689811988 has 12 divisors (see below), whose sum is σ = 1215983412. Its totient is φ = 342388160.

The previous prime is 689811959. The next prime is 689812027. The reversal of 689811988 is 889118986.

It can be written as a sum of positive squares in 2 ways, for example, as 530749444 + 159062544 = 23038^2 + 12612^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 628843 + ... + 629938.

It is an arithmetic number, because the mean of its divisors is an integer number (101331951).

Almost surely, 2^689811988 is an apocalyptic number.

It is an amenable number.

689811988 is a deficient number, since it is larger than the sum of its proper divisors (526171424).

689811988 is a wasteful number, since it uses less digits than its factorization.

689811988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1258922 (or 1258920 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 58.

The square root of 689811988 is about 26264.2720820509. The cubic root of 689811988 is about 883.5753251161.

The spelling of 689811988 in words is "six hundred eighty-nine million, eight hundred eleven thousand, nine hundred eighty-eight".