520731 has 6 divisors (see below), whose sum is σ = 752180. Its totient is φ = 347148.

The previous prime is 520721. The next prime is 520747. The reversal of 520731 is 137025.

It is not a de Polignac number, because 520731 - 2⁵ = 520699 is a prime.

It is a super-3 number, since 3×520731³ = 423605463581333673, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (520721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 28921 + ... + 28938.

2⁵²⁰⁷³¹ is an apocalyptic number.

520731 is a deficient number, since it is larger than the sum of its proper divisors (231449).

520731 is a wasteful number, since it uses less digits than its factorization.

520731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57865 (or 57862 counting only the distinct ones).

The product of its (nonzero) digits is 210, while the sum is 18.

The square root of 520731 is about 721.6169343911. The cubic root of 520731 is about 80.4521789455.

Adding to 520731 its reverse (137025), we get a palindrome (657756).

It can be divided in two parts, 5 and 20731, that added together give a 4-th power (20736 = 12⁴).

The spelling of 520731 in words is "five hundred twenty thousand, seven hundred thirty-one".