520224721 has 2 divisors, whose sum is σ = 520224722. Its totient is φ = 520224720.

The previous prime is 520224697. The next prime is 520224779. The reversal of 520224721 is 127422025.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 508051600 + 12173121 = 22540^2 + 3489^2 .

It is a cyclic number.

It is not a de Polignac number, because 520224721 - 2¹⁷ = 520093649 is a prime.

It is not a weakly prime, because it can be changed into another prime (520224781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260112360 + 260112361.

It is an arithmetic number, because the mean of its divisors is an integer number (260112361).

Almost surely, 2^520224721 is an apocalyptic number.

It is an amenable number.

520224721 is a deficient number, since it is larger than the sum of its proper divisors (1).

520224721 is an equidigital number, since it uses as much as digits as its factorization.

520224721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2240, while the sum is 25.

The square root of 520224721 is about 22808.4353036327. The cubic root of 520224721 is about 804.2609736906.

Adding to 520224721 its reverse (127422025), we get a palindrome (647646746).

The spelling of 520224721 in words is "five hundred twenty million, two hundred twenty-four thousand, seven hundred twenty-one".