687422909 has 2 divisors, whose sum is σ = 687422910. Its totient is φ = 687422908.

The previous prime is 687422843. The next prime is 687422921. The reversal of 687422909 is 909224786.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 684607225 + 2815684 = 26165^2 + 1678^2 .

It is a cyclic number.

It is not a de Polignac number, because 687422909 - 2²⁴ = 670645693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (687422609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343711454 + 343711455.

It is an arithmetic number, because the mean of its divisors is an integer number (343711455).

Almost surely, 2^687422909 is an apocalyptic number.

It is an amenable number.

687422909 is a deficient number, since it is larger than the sum of its proper divisors (1).

687422909 is an equidigital number, since it uses as much as digits as its factorization.

687422909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 435456, while the sum is 47.

The square root of 687422909 is about 26218.7510953516. The cubic root of 687422909 is about 882.5540937398.

The spelling of 687422909 in words is "six hundred eighty-seven million, four hundred twenty-two thousand, nine hundred nine".