500661221 has 4 divisors (see below), whose sum is σ = 508868844. Its totient is φ = 492453600.

The previous prime is 500661163. The next prime is 500661251. The reversal of 500661221 is 122166005.

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 54184321 + 446476900 = 7361^2 + 21130^2 .

It is a cyclic number.

It is not a de Polignac number, because 500661221 - 2¹⁰ = 500660197 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 (500661251) 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, 4103720 + ... + 4103841.

It is an arithmetic number, because the mean of its divisors is an integer number (127217211).

Almost surely, 2^500661221 is an apocalyptic number.

It is an amenable number.

500661221 is a deficient number, since it is larger than the sum of its proper divisors (8207623).

500661221 is an equidigital number, since it uses as much as digits as its factorization.

500661221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8207622.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 500661221 is about 22375.4602410766. The cubic root of 500661221 is about 794.0502461715.

The spelling of 500661221 in words is "five hundred million, six hundred sixty-one thousand, two hundred twenty-one".