688513817 has 4 divisors (see below), whose sum is σ = 688776576. Its totient is φ = 688251060.

The previous prime is 688513781. The next prime is 688513907. The reversal of 688513817 is 718315886.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 688513817 - 2⁸ = 688513561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (688513517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 127409 + ... + 132702.

It is an arithmetic number, because the mean of its divisors is an integer number (172194144).

Almost surely, 2^688513817 is an apocalyptic number.

It is an amenable number.

688513817 is a deficient number, since it is larger than the sum of its proper divisors (262759).

688513817 is a wasteful number, since it uses less digits than its factorization.

688513817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262758.

The product of its digits is 322560, while the sum is 47.

The square root of 688513817 is about 26239.5468139219. The cubic root of 688513817 is about 883.0207043511.

It can be divided in two parts, 6885 and 13817, that added together give a palindrome (20702).

The spelling of 688513817 in words is "six hundred eighty-eight million, five hundred thirteen thousand, eight hundred seventeen".