520728321 has 16 divisors (see below), whose sum is σ = 723916800. Its totient is φ = 332535168.

The previous prime is 520728319. The next prime is 520728371. The reversal of 520728321 is 123827025.

It is not a de Polignac number, because 520728321 - 2¹ = 520728319 is a prime.

It is not an unprimeable number, because it can be changed into a prime (520728311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12516 + ... + 34613.

It is an arithmetic number, because the mean of its divisors is an integer number (45244800).

Almost surely, 2^520728321 is an apocalyptic number.

It is an amenable number.

520728321 is a deficient number, since it is larger than the sum of its proper divisors (203188479).

520728321 is a wasteful number, since it uses less digits than its factorization.

520728321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47288.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 520728321 is about 22819.4724084498. The cubic root of 520728321 is about 804.5204097805.

The spelling of 520728321 in words is "five hundred twenty million, seven hundred twenty-eight thousand, three hundred twenty-one".