688394304 has 168 divisors, whose sum is σ = 2142667800. Its totient is φ = 210051072.

The previous prime is 688394293. The next prime is 688394321. The reversal of 688394304 is 403493886.

It can be written as a sum of positive squares in 4 ways, for example, as 71368704 + 617025600 = 8448^2 + 24840^2 .

It is a super-5 number, since 5×688394304⁵ (a number of 45 digits) contains 55555 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 688394304.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1115404 + ... + 1116020.

It is an arithmetic number, because the mean of its divisors is an integer number (12753975).

Almost surely, 2^688394304 is an apocalyptic number.

688394304 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688394304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1071333900).

688394304 is an abundant number, since it is smaller than the sum of its proper divisors (1454273496).

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

688394304 is a wasteful number, since it uses less digits than its factorization.

688394304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797 (or 784 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The square root of 688394304 is about 26237.2693701155. The cubic root of 688394304 is about 882.9696094868.

The spelling of 688394304 in words is "six hundred eighty-eight million, three hundred ninety-four thousand, three hundred four".