513985909 has 2 divisors, whose sum is σ = 513985910. Its totient is φ = 513985908.

The previous prime is 513985819. The next prime is 513985931. The reversal of 513985909 is 909589315.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 434722500 + 79263409 = 20850^2 + 8903^2 .

It is a cyclic number.

It is not a de Polignac number, because 513985909 - 2¹⁹ = 513461621 is a prime.

It is a super-3 number, since 3×513985909³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213985909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 256992954 + 256992955.

It is an arithmetic number, because the mean of its divisors is an integer number (256992955).

Almost surely, 2^513985909 is an apocalyptic number.

It is an amenable number.

513985909 is a deficient number, since it is larger than the sum of its proper divisors (1).

513985909 is an equidigital number, since it uses as much as digits as its factorization.

513985909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 437400, while the sum is 49.

The square root of 513985909 is about 22671.2573316964. The cubic root of 513985909 is about 801.0329931864.

The spelling of 513985909 in words is "five hundred thirteen million, nine hundred eighty-five thousand, nine hundred nine".