520821317 has 2 divisors, whose sum is σ = 520821318. Its totient is φ = 520821316.

The previous prime is 520821263. The next prime is 520821337. The reversal of 520821317 is 713128025.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 487482241 + 33339076 = 22079^2 + 5774^2 .

It is a cyclic number.

It is not a de Polignac number, because 520821317 - 2²⁰ = 519772741 is a prime.

It is a super-2 number, since 2×520821317² = 542509688483228978, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 520821317.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (520821337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260410658 + 260410659.

It is an arithmetic number, because the mean of its divisors is an integer number (260410659).

Almost surely, 2^520821317 is an apocalyptic number.

It is an amenable number.

520821317 is a deficient number, since it is larger than the sum of its proper divisors (1).

520821317 is an equidigital number, since it uses as much as digits as its factorization.

520821317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 520821317 is about 22821.5099631904. The cubic root of 520821317 is about 804.5682995812.

The spelling of 520821317 in words is "five hundred twenty million, eight hundred twenty-one thousand, three hundred seventeen".