688531489 has 2 divisors, whose sum is σ = 688531490. Its totient is φ = 688531488.

The previous prime is 688531471. The next prime is 688531513. The reversal of 688531489 is 984135886.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 445421025 + 243110464 = 21105^2 + 15592^2 .

It is a cyclic number.

It is not a de Polignac number, because 688531489 - 2¹⁷ = 688400417 is a prime.

It is a super-2 number, since 2×688531489² = 948151222689114242, which contains 22 as substring.

It is equal to p_35689498 and since 688531489 and 35689498 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (688531439) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344265744 + 344265745.

It is an arithmetic number, because the mean of its divisors is an integer number (344265745).

Almost surely, 2^688531489 is an apocalyptic number.

It is an amenable number.

688531489 is a deficient number, since it is larger than the sum of its proper divisors (1).

688531489 is an equidigital number, since it uses as much as digits as its factorization.

688531489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1658880, while the sum is 52.

The square root of 688531489 is about 26239.8835553819. The cubic root of 688531489 is about 883.0282590813.

The spelling of 688531489 in words is "six hundred eighty-eight million, five hundred thirty-one thousand, four hundred eighty-nine".