687389 has 2 divisors, whose sum is σ = 687390. Its totient is φ = 687388.

The previous prime is 687383. The next prime is 687397. The reversal of 687389 is 983786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 466489 + 220900 = 683^2 + 470^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-687389 is a prime.

It is a super-3 number, since 3×687389³ = 974381408263334607, which contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343694 + 343695.

It is an arithmetic number, because the mean of its divisors is an integer number (343695).

2⁶⁸⁷³⁸⁹ is an apocalyptic number.

It is an amenable number.

687389 is a deficient number, since it is larger than the sum of its proper divisors (1).

687389 is an equidigital number, since it uses as much as digits as its factorization.

687389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 41.

The square root of 687389 is about 829.0892593684. The cubic root of 687389 is about 88.2539582043.

The spelling of 687389 in words is "six hundred eighty-seven thousand, three hundred eighty-nine".