689945568768 has 560 divisors, whose sum is σ = 2189763417600. Its totient is φ = 216468910080.

The previous prime is 689945568743. The next prime is 689945568817. The reversal of 689945568768 is 867865549986.

689945568768 is a `hidden beast` number, since 6 + 8 + 9 + 9 + 45 + 568 + 7 + 6 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a congruent number.

It is an unprimeable number.

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 55 ways as a sum of consecutive naturals, for example, 1921853773 + ... + 1921854131.

Almost surely, 2^689945568768 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 689945568768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1094881708800).

689945568768 is an abundant number, since it is smaller than the sum of its proper divisors (1499817848832).

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

689945568768 is an equidigital number, since it uses as much as digits as its factorization.

689945568768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 685 (or 654 counting only the distinct ones).

The product of its digits is 6270566400, while the sum is 81.

The spelling of 689945568768 in words is "six hundred eighty-nine billion, nine hundred forty-five million, five hundred sixty-eight thousand, seven hundred sixty-eight".