688675644 has 72 divisors (see below), whose sum is σ = 1906828560. Its totient is φ = 208599552.

The previous prime is 688675619. The next prime is 688675667. The reversal of 688675644 is 446576886.

It is a congruent number.

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, 1654 + ... + 37149.

It is an arithmetic number, because the mean of its divisors is an integer number (26483730).

Almost surely, 2^688675644 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 688675644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (953414280).

688675644 is an abundant number, since it is smaller than the sum of its proper divisors (1218152916).

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

688675644 is a wasteful number, since it uses less digits than its factorization.

688675644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38859 (or 38854 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 54.

The square root of 688675644 is about 26242.6302797566. The cubic root of 688675644 is about 883.0898801101.

The spelling of 688675644 in words is "six hundred eighty-eight million, six hundred seventy-five thousand, six hundred forty-four".