8139609 has 15 divisors (see below), whose sum is σ = 12197647. Its totient is φ = 5409288.

The previous prime is 8139589. The next prime is 8139611. The reversal of 8139609 is 9069318.

The square root of 8139609 is 2853.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 455625 + 7683984 = 675^2 + 2772^2 .

It is not a de Polignac number, because 8139609 - 2¹⁷ = 8008537 is a prime.

It is a Duffinian number.

8139609 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (8139409) 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 in 14 ways as a sum of consecutive naturals, for example, 25519 + ... + 25835.

Almost surely, 2^8139609 is an apocalyptic number.

8139609 is the 2853-rd square number.

8139609 is the 1427-th centered octagonal number.

It is an amenable number.

8139609 is a deficient number, since it is larger than the sum of its proper divisors (4058038).

8139609 is an frugal number, since it uses more digits than its factorization.

8139609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 646 (or 320 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The cubic root of 8139609 is about 201.1567055972.

Multiplying 8139609 by its sum of digits (36), we get a square (293025924 = 17118²).

Multiplying 8139609 by its product of nonzero digits (11664), we get a square (94940399376 = 308124²).

The spelling of 8139609 in words is "eight million, one hundred thirty-nine thousand, six hundred nine".