520216121 has 2 divisors, whose sum is σ = 520216122. Its totient is φ = 520216120.

The previous prime is 520216117. The next prime is 520216129. The reversal of 520216121 is 121612025.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 316840000 + 203376121 = 17800^2 + 14261^2 .

It is a cyclic number.

It is not a de Polignac number, because 520216121 - 2² = 520216117 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 520216093 and 520216102.

It is not a weakly prime, because it can be changed into another prime (520216129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260108060 + 260108061.

It is an arithmetic number, because the mean of its divisors is an integer number (260108061).

Almost surely, 2^520216121 is an apocalyptic number.

It is an amenable number.

520216121 is a deficient number, since it is larger than the sum of its proper divisors (1).

520216121 is an equidigital number, since it uses as much as digits as its factorization.

520216121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 520216121 is about 22808.2467761115. The cubic root of 520216121 is about 804.2565418350.

Adding to 520216121 its reverse (121612025), we get a palindrome (641828146).

The spelling of 520216121 in words is "five hundred twenty million, two hundred sixteen thousand, one hundred twenty-one".