688389539 has 4 divisors (see below), whose sum is σ = 688635024. Its totient is φ = 688144056.

The previous prime is 688389509. The next prime is 688389601. The reversal of 688389539 is 935983886.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 688389539 - 2⁸ = 688389283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688389509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 118487 + ... + 124160.

It is an arithmetic number, because the mean of its divisors is an integer number (172158756).

Almost surely, 2^688389539 is an apocalyptic number.

688389539 is a deficient number, since it is larger than the sum of its proper divisors (245485).

688389539 is a wasteful number, since it uses less digits than its factorization.

688389539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245484.

The product of its digits is 11197440, while the sum is 59.

The square root of 688389539 is about 26237.1785640148. The cubic root of 688389539 is about 882.9675722048.

The spelling of 688389539 in words is "six hundred eighty-eight million, three hundred eighty-nine thousand, five hundred thirty-nine".