520216321 has 4 divisors (see below), whose sum is σ = 520461892. Its totient is φ = 519970752.

The previous prime is 520216309. The next prime is 520216331. The reversal of 520216321 is 123612025.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 276856321 + 243360000 = 16639^2 + 15600^2 .

It is a cyclic number.

It is not a de Polignac number, because 520216321 - 2⁵ = 520216289 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 520216292 and 520216301.

It is not an unprimeable number, because it can be changed into a prime (520216331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 119580 + ... + 123853.

It is an arithmetic number, because the mean of its divisors is an integer number (130115473).

Almost surely, 2^520216321 is an apocalyptic number.

It is an amenable number.

520216321 is a deficient number, since it is larger than the sum of its proper divisors (245571).

520216321 is a wasteful number, since it uses less digits than its factorization.

520216321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245570.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 520216321 is about 22808.2511604901. The cubic root of 520216321 is about 804.2566449020.

Adding to 520216321 its reverse (123612025), we get a palindrome (643828346).

The spelling of 520216321 in words is "five hundred twenty million, two hundred sixteen thousand, three hundred twenty-one".