520045021 has 2 divisors, whose sum is σ = 520045022. Its totient is φ = 520045020.

The previous prime is 520044971. The next prime is 520045087. The reversal of 520045021 is 120540025.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 475676100 + 44368921 = 21810^2 + 6661^2 .

It is a cyclic number.

It is not a de Polignac number, because 520045021 - 2⁷ = 520044893 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 520045021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (520045091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260022510 + 260022511.

It is an arithmetic number, because the mean of its divisors is an integer number (260022511).

Almost surely, 2^520045021 is an apocalyptic number.

It is an amenable number.

520045021 is a deficient number, since it is larger than the sum of its proper divisors (1).

520045021 is an equidigital number, since it uses as much as digits as its factorization.

520045021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 520045021 is about 22804.4956313443. The cubic root of 520045021 is about 804.1683583679.

Adding to 520045021 its reverse (120540025), we get a palindrome (640585046).

The spelling of 520045021 in words is "five hundred twenty million, forty-five thousand, twenty-one".