688758561391 has 2 divisors, whose sum is σ = 688758561392. Its totient is φ = 688758561390.

The previous prime is 688758561373. The next prime is 688758561401. The reversal of 688758561391 is 193165857886.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688758561391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688758561371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344379280695 + 344379280696.

It is an arithmetic number, because the mean of its divisors is an integer number (344379280696).

Almost surely, 2^688758561391 is an apocalyptic number.

688758561391 is a deficient number, since it is larger than the sum of its proper divisors (1).

688758561391 is an equidigital number, since it uses as much as digits as its factorization.

688758561391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 87091200, while the sum is 67.

The spelling of 688758561391 in words is "six hundred eighty-eight billion, seven hundred fifty-eight million, five hundred sixty-one thousand, three hundred ninety-one".