505541221 has 4 divisors (see below), whose sum is σ = 513828844. Its totient is φ = 497253600.

The previous prime is 505541213. The next prime is 505541243. The reversal of 505541221 is 122145505.

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 181037025 + 324504196 = 13455^2 + 18014^2 .

It is a cyclic number.

It is not a de Polignac number, because 505541221 - 2³ = 505541213 is a prime.

It is a super-2 number, since 2×505541221² = 511143852260341682, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (505541251) 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, 4143720 + ... + 4143841.

It is an arithmetic number, because the mean of its divisors is an integer number (128457211).

Almost surely, 2^505541221 is an apocalyptic number.

It is an amenable number.

505541221 is a deficient number, since it is larger than the sum of its proper divisors (8287623).

505541221 is an equidigital number, since it uses as much as digits as its factorization.

505541221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8287622.

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 505541221 is about 22484.2438387418. The cubic root of 505541221 is about 796.6218074525.

Adding to 505541221 its reverse (122145505), we get a palindrome (627686726).

The spelling of 505541221 in words is "five hundred five million, five hundred forty-one thousand, two hundred twenty-one".