688171728 has 40 divisors (see below), whose sum is σ = 1835128576. Its totient is φ = 221990400.

The previous prime is 688171721. The next prime is 688171733. The reversal of 688171728 is 827171886.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688171721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 229753 + ... + 232728.

Almost surely, 2^688171728 is an apocalyptic number.

It is an amenable number.

688171728 is an abundant number, since it is smaller than the sum of its proper divisors (1146956848).

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

688171728 is a wasteful number, since it uses less digits than its factorization.

688171728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462523 (or 462517 counting only the distinct ones).

The product of its digits is 301056, while the sum is 48.

The square root of 688171728 is about 26233.0274272719. The cubic root of 688171728 is about 882.8744367893.

The spelling of 688171728 in words is "six hundred eighty-eight million, one hundred seventy-one thousand, seven hundred twenty-eight".