688943728 has 20 divisors (see below), whose sum is σ = 1456176888. Its totient is φ = 313156160.

The previous prime is 688943707. The next prime is 688943747. The reversal of 688943728 is 827349886.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1957051 + ... + 1957402.

Almost surely, 2^688943728 is an apocalyptic number.

It is an amenable number.

688943728 is an abundant number, since it is smaller than the sum of its proper divisors (767233160).

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

688943728 is a wasteful number, since it uses less digits than its factorization.

688943728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3914472 (or 3914466 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 55.

The square root of 688943728 is about 26247.7375786943. The cubic root of 688943728 is about 883.2044534253.

The spelling of 688943728 in words is "six hundred eighty-eight million, nine hundred forty-three thousand, seven hundred twenty-eight".