688377509 has 2 divisors, whose sum is σ = 688377510. Its totient is φ = 688377508.

The previous prime is 688377499. The next prime is 688377523. The reversal of 688377509 is 905773886.

688377509 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 630160609 + 58216900 = 25103^2 + 7630^2 .

It is a cyclic number.

It is not a de Polignac number, because 688377509 - 2⁴ = 688377493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (688379509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 344188754 + 344188755.

It is an arithmetic number, because the mean of its divisors is an integer number (344188755).

Almost surely, 2^688377509 is an apocalyptic number.

It is an amenable number.

688377509 is a deficient number, since it is larger than the sum of its proper divisors (1).

688377509 is an equidigital number, since it uses as much as digits as its factorization.

688377509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2540160, while the sum is 53.

The square root of 688377509 is about 26236.9493081799. The cubic root of 688377509 is about 882.9624287208.

It can be divided in two parts, 688377 and 509, that added together give a palindrome (688886).

The spelling of 688377509 in words is "six hundred eighty-eight million, three hundred seventy-seven thousand, five hundred nine".