1005000221 has 4 divisors (see below), whose sum is σ = 1005485244. Its totient is φ = 1004515200.

The previous prime is 1005000209. The next prime is 1005000223. The reversal of 1005000221 is 1220005001.

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 489028996 + 515971225 = 22114^2 + 22715^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1005000221 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 (1005000223) 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, 239390 + ... + 243551.

It is an arithmetic number, because the mean of its divisors is an integer number (251371311).

Almost surely, 2^1005000221 is an apocalyptic number.

It is an amenable number.

1005000221 is a deficient number, since it is larger than the sum of its proper divisors (485023).

1005000221 is an equidigital number, since it uses as much as digits as its factorization.

1005000221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 485022.

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 1005000221 is about 31701.7384539082. The cubic root of 1005000221 is about 1001.6639700014.

Adding to 1005000221 its reverse (1220005001), we get a palindrome (2225005222).

The spelling of 1005000221 in words is "one billion, five million, two hundred twenty-one", and thus it is an aban number.