689659668 has 18 divisors (see below), whose sum is σ = 1743306474. Its totient is φ = 229886544.

The previous prime is 689659667. The next prime is 689659681. The reversal of 689659668 is 866956986.

689659668 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 610485264 + 79174404 = 24708^2 + 8898^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (689659667) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9578571 + ... + 9578642.

Almost surely, 2^689659668 is an apocalyptic number.

It is an amenable number.

689659668 is an abundant number, since it is smaller than the sum of its proper divisors (1053646806).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

689659668 is a wasteful number, since it uses less digits than its factorization.

689659668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19157223 (or 19157218 counting only the distinct ones).

The product of its digits is 33592320, while the sum is 63.

The square root of 689659668 is about 26261.3721652163. The cubic root of 689659668 is about 883.5102851229.

It can be divided in two parts, 6896 and 59668, that added together give a square (66564 = 258²).

The spelling of 689659668 in words is "six hundred eighty-nine million, six hundred fifty-nine thousand, six hundred sixty-eight".