8138509 has 2 divisors, whose sum is σ = 8138510. Its totient is φ = 8138508.

The previous prime is 8138497. The next prime is 8138513. The reversal of 8138509 is 9058318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5076009 + 3062500 = 2253^2 + 1750^2 .

It is a cyclic number.

It is not a de Polignac number, because 8138509 - 2⁵ = 8138477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8138539) 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, 4069254 + 4069255.

It is an arithmetic number, because the mean of its divisors is an integer number (4069255).

Almost surely, 2^8138509 is an apocalyptic number.

It is an amenable number.

8138509 is a deficient number, since it is larger than the sum of its proper divisors (1).

8138509 is an equidigital number, since it uses as much as digits as its factorization.

8138509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 8138509 is about 2852.8072139561. The cubic root of 8138509 is about 201.1476436408.

The spelling of 8138509 in words is "eight million, one hundred thirty-eight thousand, five hundred nine".