520779509 has 8 divisors (see below), whose sum is σ = 546393600. Its totient is φ = 495716400.

The previous prime is 520779503. The next prime is 520779529. The reversal of 520779509 is 905977025.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-520779509 is a prime.

It is a super-2 number, since 2×520779509² = 542422593988562162, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 520779509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (520779503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 135809 + ... + 139590.

It is an arithmetic number, because the mean of its divisors is an integer number (68299200).

Almost surely, 2^520779509 is an apocalyptic number.

It is an amenable number.

520779509 is a deficient number, since it is larger than the sum of its proper divisors (25614091).

520779509 is a wasteful number, since it uses less digits than its factorization.

520779509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 275491.

The product of its (nonzero) digits is 198450, while the sum is 44.

The square root of 520779509 is about 22820.5939668537. The cubic root of 520779509 is about 804.5467705779.

The spelling of 520779509 in words is "five hundred twenty million, seven hundred seventy-nine thousand, five hundred nine".