687382309 has 2 divisors, whose sum is σ = 687382310. Its totient is φ = 687382308.

The previous prime is 687382307. The next prime is 687382349. The reversal of 687382309 is 903283786.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 627753025 + 59629284 = 25055^2 + 7722^2 .

It is a cyclic number.

It is not a de Polignac number, because 687382309 - 2¹ = 687382307 is a prime.

Together with 687382307, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687382303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343691154 + 343691155.

It is an arithmetic number, because the mean of its divisors is an integer number (343691155).

Almost surely, 2^687382309 is an apocalyptic number.

It is an amenable number.

687382309 is a deficient number, since it is larger than the sum of its proper divisors (1).

687382309 is an equidigital number, since it uses as much as digits as its factorization.

687382309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 46.

The square root of 687382309 is about 26217.9768288859. The cubic root of 687382309 is about 882.5367185058.

The spelling of 687382309 in words is "six hundred eighty-seven million, three hundred eighty-two thousand, three hundred nine".