520213021 has 4 divisors (see below), whose sum is σ = 520258912. Its totient is φ = 520167132.

The previous prime is 520213013. The next prime is 520213051. The reversal of 520213021 is 120312025.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 520213021 - 2³ = 520213013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 520212986 and 520213004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520213051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7720 + ... + 33166.

It is an arithmetic number, because the mean of its divisors is an integer number (130064728).

Almost surely, 2^520213021 is an apocalyptic number.

It is an amenable number.

520213021 is a deficient number, since it is larger than the sum of its proper divisors (45891).

520213021 is a wasteful number, since it uses less digits than its factorization.

520213021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45890.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 520213021 is about 22808.1788181345. The cubic root of 520213021 is about 804.2549442937.

Adding to 520213021 its reverse (120312025), we get a palindrome (640525046).

The spelling of 520213021 in words is "five hundred twenty million, two hundred thirteen thousand, twenty-one".