520439509 has 2 divisors, whose sum is σ = 520439510. Its totient is φ = 520439508.

The previous prime is 520439497. The next prime is 520439519. The reversal of 520439509 is 905934025.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 318515409 + 201924100 = 17847^2 + 14210^2 .

It is a cyclic number.

It is not a de Polignac number, because 520439509 - 2⁵ = 520439477 is a prime.

It is a super-2 number, since 2×520439509² = 541714565056322162, which contains 22 as substring.

It is equal to p_27374464 and since 520439509 and 27374464 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (520439519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260219754 + 260219755.

It is an arithmetic number, because the mean of its divisors is an integer number (260219755).

Almost surely, 2^520439509 is an apocalyptic number.

It is an amenable number.

520439509 is a deficient number, since it is larger than the sum of its proper divisors (1).

520439509 is an equidigital number, since it uses as much as digits as its factorization.

520439509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48600, while the sum is 37.

The square root of 520439509 is about 22813.1433388738. The cubic root of 520439509 is about 804.3716449898.

The spelling of 520439509 in words is "five hundred twenty million, four hundred thirty-nine thousand, five hundred nine".