688987040 has 72 divisors (see below), whose sum is σ = 1893505572. Its totient is φ = 236221440.

The previous prime is 688987037. The next prime is 688987081. The reversal of 688987040 is 40789886.

It can be written as a sum of positive squares in 2 ways, for example, as 688327696 + 659344 = 26236^2 + 812^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 688987040.

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 11 ways as a sum of consecutive naturals, for example, 36101 + ... + 51780.

Almost surely, 2^688987040 is an apocalyptic number.

It is an amenable number.

688987040 is an abundant number, since it is smaller than the sum of its proper divisors (1204518532).

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

688987040 is a wasteful number, since it uses less digits than its factorization.

688987040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87910 (or 87895 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 50.

The square root of 688987040 is about 26248.5626273135. The cubic root of 688987040 is about 883.2229612502. Note that the first 3 decimals are identical.

The spelling of 688987040 in words is "six hundred eighty-eight million, nine hundred eighty-seven thousand, forty".