688621108 has 54 divisors (see below), whose sum is σ = 1489269894. Its totient is φ = 277740288.

The previous prime is 688621099. The next prime is 688621121. The reversal of 688621108 is 801126886.

It can be written as a sum of positive squares in 3 ways, for example, as 106750224 + 581870884 = 10332^2 + 24122^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 50566 + ... + 62722.

Almost surely, 2^688621108 is an apocalyptic number.

688621108 is a gapful number since it is divisible by the number (68) 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 688621108, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (744634947).

688621108 is an abundant number, since it is smaller than the sum of its proper divisors (800648786).

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

688621108 is a wasteful number, since it uses less digits than its factorization.

688621108 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12209 (or 12183 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 40.

The square root of 688621108 is about 26241.5911865115. The cubic root of 688621108 is about 883.0665689614.

The spelling of 688621108 in words is "six hundred eighty-eight million, six hundred twenty-one thousand, one hundred eight".