520605565 has 4 divisors (see below), whose sum is σ = 624726684. Its totient is φ = 416484448.

The previous prime is 520605551. The next prime is 520605571. The reversal of 520605565 is 565506025.

It is a happy number.

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 120165444 + 400440121 = 10962^2 + 20011^2 .

It is a cyclic number.

It is not a de Polignac number, because 520605565 - 2⁹ = 520605053 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 520605565.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52060552 + ... + 52060561.

It is an arithmetic number, because the mean of its divisors is an integer number (156181671).

Almost surely, 2^520605565 is an apocalyptic number.

It is an amenable number.

520605565 is a deficient number, since it is larger than the sum of its proper divisors (104121119).

520605565 is a wasteful number, since it uses less digits than its factorization.

520605565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104121118.

The product of its (nonzero) digits is 45000, while the sum is 34.

The square root of 520605565 is about 22816.7825295329. The cubic root of 520605565 is about 804.4571858529.

The spelling of 520605565 in words is "five hundred twenty million, six hundred five thousand, five hundred sixty-five".