688637736889 has 2 divisors, whose sum is σ = 688637736890. Its totient is φ = 688637736888.

The previous prime is 688637736851. The next prime is 688637736949. The reversal of 688637736889 is 988637736886.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 686233305664 + 2404431225 = 828392^2 + 49035^2 .

It is a cyclic number.

It is not a de Polignac number, because 688637736889 - 2¹⁵ = 688637704121 is a prime.

It is not a weakly prime, because it can be changed into another prime (688637736989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344318868444 + 344318868445.

It is an arithmetic number, because the mean of its divisors is an integer number (344318868445).

Almost surely, 2^688637736889 is an apocalyptic number.

It is an amenable number.

688637736889 is a deficient number, since it is larger than the sum of its proper divisors (1).

688637736889 is an equidigital number, since it uses as much as digits as its factorization.

688637736889 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3511517184, while the sum is 79.

The spelling of 688637736889 in words is "six hundred eighty-eight billion, six hundred thirty-seven million, seven hundred thirty-six thousand, eight hundred eighty-nine".