688768257 has 4 divisors (see below), whose sum is σ = 918357680. Its totient is φ = 459178836.

The previous prime is 688768247. The next prime is 688768273. The reversal of 688768257 is 752867886.

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 not a de Polignac number, because 688768257 - 2¹¹ = 688766209 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 688768197 and 688768206.

It is not an unprimeable number, because it can be changed into a prime (688768247) 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 3 ways as a sum of consecutive naturals, for example, 114794707 + ... + 114794712.

It is an arithmetic number, because the mean of its divisors is an integer number (229589420).

Almost surely, 2^688768257 is an apocalyptic number.

It is an amenable number.

688768257 is a deficient number, since it is larger than the sum of its proper divisors (229589423).

688768257 is a wasteful number, since it uses less digits than its factorization.

688768257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229589422.

The product of its digits is 9031680, while the sum is 57.

The square root of 688768257 is about 26244.3947729796. The cubic root of 688768257 is about 883.1294642684.

The spelling of 688768257 in words is "six hundred eighty-eight million, seven hundred sixty-eight thousand, two hundred fifty-seven".