688730642 has 16 divisors (see below), whose sum is σ = 1041072000. Its totient is φ = 341716320.

The previous prime is 688730641. The next prime is 688730663. The reversal of 688730642 is 246037886.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 688730593 and 688730602.

It is not an unprimeable number, because it can be changed into a prime (688730641) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 160667 + ... + 164897.

It is an arithmetic number, because the mean of its divisors is an integer number (65067000).

Almost surely, 2^688730642 is an apocalyptic number.

688730642 is a deficient number, since it is larger than the sum of its proper divisors (352341358).

688730642 is a wasteful number, since it uses less digits than its factorization.

688730642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4841.

The product of its (nonzero) digits is 387072, while the sum is 44.

The square root of 688730642 is about 26243.6781339811. The cubic root of 688730642 is about 883.1133874921.

The spelling of 688730642 in words is "six hundred eighty-eight million, seven hundred thirty thousand, six hundred forty-two".