688780 has 12 divisors (see below), whose sum is σ = 1446480. Its totient is φ = 275504.

The previous prime is 688777. The next prime is 688783. The reversal of 688780 is 87886.

It is an interprime number because it is at equal distance from previous prime (688777) and next prime (688783).

It is not an unprimeable number, because it can be changed into a prime (688783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17200 + ... + 17239.

It is an arithmetic number, because the mean of its divisors is an integer number (120540).

2⁶⁸⁸⁷⁸⁰ is an apocalyptic number.

It is an amenable number.

688780 is an abundant number, since it is smaller than the sum of its proper divisors (757700).

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

688780 is a wasteful number, since it uses less digits than its factorization.

688780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34448 (or 34446 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 688780 is about 829.9277076951. The cubic root of 688780 is about 88.3134483146.

The spelling of 688780 in words is "six hundred eighty-eight thousand, seven hundred eighty".