1005011221 has 4 divisors (see below), whose sum is σ = 1018778572. Its totient is φ = 991243872.

The previous prime is 1005011209. The next prime is 1005011237. The reversal of 1005011221 is 1221105001.

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 478996996 + 526014225 = 21886^2 + 22935^2 .

It is a cyclic number.

It is not a de Polignac number, because 1005011221 - 2¹⁵ = 1004978453 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 (1005011291) 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, 6883566 + ... + 6883711.

It is an arithmetic number, because the mean of its divisors is an integer number (254694643).

Almost surely, 2^1005011221 is an apocalyptic number.

It is an amenable number.

1005011221 is a deficient number, since it is larger than the sum of its proper divisors (13767351).

1005011221 is an equidigital number, since it uses as much as digits as its factorization.

1005011221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13767350.

The product of its (nonzero) digits is 20, while the sum is 13.

The square root of 1005011221 is about 31701.9119454963. The cubic root of 1005011221 is about 1001.6676244827.

Adding to 1005011221 its reverse (1221105001), we get a palindrome (2226116222).

The spelling of 1005011221 in words is "one billion, five million, eleven thousand, two hundred twenty-one".