688385828 has 24 divisors (see below), whose sum is σ = 1373658552. Its totient is φ = 299026944.

The previous prime is 688385821. The next prime is 688385833. The reversal of 688385828 is 828583886.

688385828 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 4 ways, for example, as 129914404 + 558471424 = 11398^2 + 23632^2 .

It is not an unprimeable number, because it can be changed into a prime (688385821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 388475 + ... + 390242.

It is an arithmetic number, because the mean of its divisors is an integer number (57235773).

Almost surely, 2^688385828 is an apocalyptic number.

688385828 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

688385828 is a deficient number, since it is larger than the sum of its proper divisors (685272724).

688385828 is a wasteful number, since it uses less digits than its factorization.

688385828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 778751 (or 778749 counting only the distinct ones).

The product of its digits is 5898240, while the sum is 56.

The square root of 688385828 is about 26237.1078436630. The cubic root of 688385828 is about 882.9659855554.

It can be divided in two parts, 6883858 and 28, that added together give a palindrome (6883886).

The spelling of 688385828 in words is "six hundred eighty-eight million, three hundred eighty-five thousand, eight hundred twenty-eight".