505821761 has 4 divisors (see below), whose sum is σ = 522138624. Its totient is φ = 489504900.

The previous prime is 505821749. The next prime is 505821779. The reversal of 505821761 is 167128505.

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 505821761 - 2⁶ = 505821697 is a prime.

It is a super-2 number, since 2×505821761² = 511711307802282242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (505821721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8158385 + ... + 8158446.

It is an arithmetic number, because the mean of its divisors is an integer number (130534656).

Almost surely, 2^505821761 is an apocalyptic number.

It is an amenable number.

505821761 is a deficient number, since it is larger than the sum of its proper divisors (16316863).

505821761 is a wasteful number, since it uses less digits than its factorization.

505821761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16316862.

The product of its (nonzero) digits is 16800, while the sum is 35.

The square root of 505821761 is about 22490.4815644308. The cubic root of 505821761 is about 796.7691366553.

The spelling of 505821761 in words is "five hundred five million, eight hundred twenty-one thousand, seven hundred sixty-one".