688665786312 has 128 divisors (see below), whose sum is σ = 2084824915200. Its totient is φ = 185057107968.

The previous prime is 688665786311. The next prime is 688665786359. The reversal of 688665786312 is 213687566886.

It is a super-2 number, since 2×688665786312² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (688665786311) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4008514 + ... + 4176782.

It is an arithmetic number, because the mean of its divisors is an integer number (16287694650).

Almost surely, 2^688665786312 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 688665786312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1042412457600).

688665786312 is an abundant number, since it is smaller than the sum of its proper divisors (1396159128888).

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

688665786312 is a wasteful number, since it uses less digits than its factorization.

688665786312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169735 (or 169731 counting only the distinct ones).

The product of its digits is 139345920, while the sum is 66.

The spelling of 688665786312 in words is "six hundred eighty-eight billion, six hundred sixty-five million, seven hundred eighty-six thousand, three hundred twelve".