520317661 has 4 divisors (see below), whose sum is σ = 542940192. Its totient is φ = 497695132.

The previous prime is 520317619. The next prime is 520317667. The reversal of 520317661 is 166713025.

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.

It is a cyclic number.

It is not a de Polignac number, because 520317661 - 2¹¹ = 520315613 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520317667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11311231 + ... + 11311276.

It is an arithmetic number, because the mean of its divisors is an integer number (135735048).

Almost surely, 2^520317661 is an apocalyptic number.

It is an amenable number.

520317661 is a deficient number, since it is larger than the sum of its proper divisors (22622531).

520317661 is a wasteful number, since it uses less digits than its factorization.

520317661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22622530.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 520317661 is about 22810.4726167609. The cubic root of 520317661 is about 804.3088655349.

The spelling of 520317661 in words is "five hundred twenty million, three hundred seventeen thousand, six hundred sixty-one".