505541809 has 4 divisors (see below), whose sum is σ = 508889920. Its totient is φ = 502193700.

The previous prime is 505541807. The next prime is 505541821. The reversal of 505541809 is 908145505.

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 505541809 - 2¹ = 505541807 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (505541807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1673829 + ... + 1674130.

It is an arithmetic number, because the mean of its divisors is an integer number (127222480).

Almost surely, 2^505541809 is an apocalyptic number.

It is an amenable number.

505541809 is a deficient number, since it is larger than the sum of its proper divisors (3348111).

505541809 is a wasteful number, since it uses less digits than its factorization.

505541809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3348110.

The product of its (nonzero) digits is 36000, while the sum is 37.

The square root of 505541809 is about 22484.2569145614. The cubic root of 505541809 is about 796.6221163053.

It can be divided in two parts, 5055 and 41809, that added together give a palindrome (46864).

The spelling of 505541809 in words is "five hundred five million, five hundred forty-one thousand, eight hundred nine".