520726021 has 4 divisors (see below), whose sum is σ = 523736172. Its totient is φ = 517715872.

The previous prime is 520726013. The next prime is 520726033. The reversal of 520726021 is 120627025.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 426422500 + 94303521 = 20650^2 + 9711^2 .

It is a cyclic number.

It is not a de Polignac number, because 520726021 - 2³ = 520726013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520726421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1504816 + ... + 1505161.

It is an arithmetic number, because the mean of its divisors is an integer number (130934043).

Almost surely, 2^520726021 is an apocalyptic number.

It is an amenable number.

520726021 is a deficient number, since it is larger than the sum of its proper divisors (3010151).

520726021 is a wasteful number, since it uses less digits than its factorization.

520726021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3010150.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 520726021 is about 22819.4220128381. The cubic root of 520726021 is about 804.5192252858.

The spelling of 520726021 in words is "five hundred twenty million, seven hundred twenty-six thousand, twenty-one".