1000221221 has 2 divisors, whose sum is σ = 1000221222. Its totient is φ = 1000221220.

The previous prime is 1000221203. The next prime is 1000221251. The reversal of 1000221221 is 1221220001.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 591170596 + 409050625 = 24314^2 + 20225^2 .

It is an emirp because it is prime and its reverse (1221220001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1000221221 - 2²² = 996026917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1000221251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500110610 + 500110611.

It is an arithmetic number, because the mean of its divisors is an integer number (500110611).

Almost surely, 2^1000221221 is an apocalyptic number.

It is an amenable number.

1000221221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1000221221 is an equidigital number, since it uses as much as digits as its factorization.

1000221221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1000221221 is about 31626.2742193892. The cubic root of 1000221221 is about 1000.0737348964.

Adding to 1000221221 its reverse (1221220001), we get a palindrome (2221441222).

The spelling of 1000221221 in words is "one billion, two hundred twenty-one thousand, two hundred twenty-one".