8731609 has 2 divisors, whose sum is σ = 8731610. Its totient is φ = 8731608.

The previous prime is 8731607. The next prime is 8731627. The reversal of 8731609 is 9061378.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8526400 + 205209 = 2920^2 + 453^2 .

It is a cyclic number.

It is not a de Polignac number, because 8731609 - 2¹ = 8731607 is a prime.

Together with 8731607, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (8731607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4365804 + 4365805.

It is an arithmetic number, because the mean of its divisors is an integer number (4365805).

Almost surely, 2^8731609 is an apocalyptic number.

It is an amenable number.

8731609 is a deficient number, since it is larger than the sum of its proper divisors (1).

8731609 is an equidigital number, since it uses as much as digits as its factorization.

8731609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 34.

The square root of 8731609 is about 2954.9296099907. The cubic root of 8731609 is about 205.9197931382.

The spelling of 8731609 in words is "eight million, seven hundred thirty-one thousand, six hundred nine".