513686321 has 2 divisors, whose sum is σ = 513686322. Its totient is φ = 513686320.

The previous prime is 513686249. The next prime is 513686323. The reversal of 513686321 is 123686315.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 329785600 + 183900721 = 18160^2 + 13561^2 .

It is a cyclic number.

It is not a de Polignac number, because 513686321 - 2¹⁰ = 513685297 is a prime.

Together with 513686323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (513686323) 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, 256843160 + 256843161.

It is an arithmetic number, because the mean of its divisors is an integer number (256843161).

Almost surely, 2^513686321 is an apocalyptic number.

It is an amenable number.

513686321 is a deficient number, since it is larger than the sum of its proper divisors (1).

513686321 is an equidigital number, since it uses as much as digits as its factorization.

513686321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 35.

The square root of 513686321 is about 22664.6491479573. The cubic root of 513686321 is about 800.8773297015.

The spelling of 513686321 in words is "five hundred thirteen million, six hundred eighty-six thousand, three hundred twenty-one".