520400660 has 24 divisors (see below), whose sum is σ = 1176906696. Its totient is φ = 192147840.

The previous prime is 520400641. The next prime is 520400681. The reversal of 520400660 is 66004025.

It can be written as a sum of positive squares in 4 ways, for example, as 743044 + 519657616 = 862^2 + 22796^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1000511 + ... + 1001030.

It is an arithmetic number, because the mean of its divisors is an integer number (49037779).

Almost surely, 2^520400660 is an apocalyptic number.

It is an amenable number.

520400660 is an abundant number, since it is smaller than the sum of its proper divisors (656506036).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

520400660 is a wasteful number, since it uses less digits than its factorization.

520400660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2001563 (or 2001561 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 520400660 is about 22812.2918620642. The cubic root of 520400660 is about 804.3516299762.

Adding to 520400660 its reverse (66004025), we get a palindrome (586404685).

The spelling of 520400660 in words is "five hundred twenty million, four hundred thousand, six hundred sixty".