688361489 has 2 divisors, whose sum is σ = 688361490. Its totient is φ = 688361488.

The previous prime is 688361477. The next prime is 688361519. The reversal of 688361489 is 984163886.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 398681089 + 289680400 = 19967^2 + 17020^2 .

It is a cyclic number.

It is not a de Polignac number, because 688361489 - 2⁴ = 688361473 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 688361489.

It is not a weakly prime, because it can be changed into another prime (688361419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344180744 + 344180745.

It is an arithmetic number, because the mean of its divisors is an integer number (344180745).

Almost surely, 2^688361489 is an apocalyptic number.

It is an amenable number.

688361489 is a deficient number, since it is larger than the sum of its proper divisors (1).

688361489 is an equidigital number, since it uses as much as digits as its factorization.

688361489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1990656, while the sum is 53.

The square root of 688361489 is about 26236.6440117634. The cubic root of 688361489 is about 882.9555792002.

The spelling of 688361489 in words is "six hundred eighty-eight million, three hundred sixty-one thousand, four hundred eighty-nine".