689785668 has 162 divisors, whose sum is σ = 2077528362. Its totient is φ = 192741120.

The previous prime is 689785637. The next prime is 689785669. The reversal of 689785668 is 866587986.

689785668 is a `hidden beast` number, since 68 + 9 + 7 + 8 + 566 + 8 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 50808384 + 638977284 = 7128^2 + 25278^2 .

It is not an unprimeable number, because it can be changed into a prime (689785669) by changing a digit.

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 53 ways as a sum of consecutive naturals, for example, 735696 + ... + 736632.

Almost surely, 2^689785668 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 689785668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1038764181).

689785668 is an abundant number, since it is smaller than the sum of its proper divisors (1387742694).

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

689785668 is a wasteful number, since it uses less digits than its factorization.

689785668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 995 (or 966 counting only the distinct ones).

The product of its digits is 34836480, while the sum is 63.

The square root of 689785668 is about 26263.7710163640. The cubic root of 689785668 is about 883.5640872722.

The spelling of 689785668 in words is "six hundred eighty-nine million, seven hundred eighty-five thousand, six hundred sixty-eight".