688908911 has 2 divisors, whose sum is σ = 688908912. Its totient is φ = 688908910.

The previous prime is 688908889. The next prime is 688908917. The reversal of 688908911 is 119809886.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-688908911 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 688908911.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688908917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344454455 + 344454456.

It is an arithmetic number, because the mean of its divisors is an integer number (344454456).

Almost surely, 2^688908911 is an apocalyptic number.

688908911 is a deficient number, since it is larger than the sum of its proper divisors (1).

688908911 is an equidigital number, since it uses as much as digits as its factorization.

688908911 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 248832, while the sum is 50.

The square root of 688908911 is about 26247.0743321994. The cubic root of 688908911 is about 883.1895750706.

The spelling of 688908911 in words is "six hundred eighty-eight million, nine hundred eight thousand, nine hundred eleven".