505788221 has 4 divisors (see below), whose sum is σ = 505858812. Its totient is φ = 505717632.

The previous prime is 505788209. The next prime is 505788247. The reversal of 505788221 is 122887505.

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 203376121 + 302412100 = 14261^2 + 17390^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-505788221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (505788121) 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, 23156 + ... + 39341.

It is an arithmetic number, because the mean of its divisors is an integer number (126464703).

Almost surely, 2^505788221 is an apocalyptic number.

It is an amenable number.

505788221 is a deficient number, since it is larger than the sum of its proper divisors (70591).

505788221 is an equidigital number, since it uses as much as digits as its factorization.

505788221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70590.

The product of its (nonzero) digits is 44800, while the sum is 38.

The square root of 505788221 is about 22489.7359032960. The cubic root of 505788221 is about 796.7515255588.

The spelling of 505788221 in words is "five hundred five million, seven hundred eighty-eight thousand, two hundred twenty-one".