520145306521 has 9 divisors (see below), whose sum is σ = 543760922271. Its totient is φ = 497514426552.

The previous prime is 520145306507. The next prime is 520145306539. The reversal of 520145306521 is 125603541025.

The square root of 520145306521 is 721211.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 389220015625 + 130925290896 = 623875^2 + 361836^2 .

It is not a de Polignac number, because 520145306521 - 2⁵ = 520145306489 is a prime.

It is a super-2 number, since 2×520145306521² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (520145316521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 16572175 + ... + 16603531.

Almost surely, 2^520145306521 is an apocalyptic number.

520145306521 is the 721211-st square number.

520145306521 is the 360606-th centered octagonal number.

It is an amenable number.

520145306521 is a deficient number, since it is larger than the sum of its proper divisors (23615615750).

520145306521 is an frugal number, since it uses more digits than its factorization.

520145306521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62760 (or 31380 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 34.

Adding to 520145306521 its reverse (125603541025), we get a palindrome (645748847546).

It can be divided in two parts, 52014 and 5306521, that added together give a palindrome (5358535).

The spelling of 520145306521 in words is "five hundred twenty billion, one hundred forty-five million, three hundred six thousand, five hundred twenty-one".