688216873909 has 2 divisors, whose sum is σ = 688216873910. Its totient is φ = 688216873908.

The previous prime is 688216873859. The next prime is 688216873919. The reversal of 688216873909 is 909378612886.

688216873909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 630221638225 + 57995235684 = 793865^2 + 240822^2 .

It is a cyclic number.

It is not a de Polignac number, because 688216873909 - 2¹⁵ = 688216841141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688216873919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344108436954 + 344108436955.

It is an arithmetic number, because the mean of its divisors is an integer number (344108436955).

Almost surely, 2^688216873909 is an apocalyptic number.

It is an amenable number.

688216873909 is a deficient number, since it is larger than the sum of its proper divisors (1).

688216873909 is an equidigital number, since it uses as much as digits as its factorization.

688216873909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 62705664, while the sum is 67.

The spelling of 688216873909 in words is "six hundred eighty-eight billion, two hundred sixteen million, eight hundred seventy-three thousand, nine hundred nine".