1000221101221 has 2 divisors, whose sum is σ = 1000221101222. Its totient is φ = 1000221101220.

The previous prime is 1000221101183. The next prime is 1000221101237. The reversal of 1000221101221 is 1221011220001.

1000221101221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 783200220196 + 217020881025 = 884986^2 + 465855^2 .

It is an emirp because it is prime and its reverse (1221011220001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1000221101221 - 2⁹ = 1000221100709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1000221101261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500110550610 + 500110550611.

It is an arithmetic number, because the mean of its divisors is an integer number (500110550611).

Almost surely, 2^{1000221101221} is an apocalyptic number.

It is an amenable number.

1000221101221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1000221101221 is an equidigital number, since it uses as much as digits as its factorization.

1000221101221 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 13.

Adding to 1000221101221 its reverse (1221011220001), we get a palindrome (2221232321222).

The spelling of 1000221101221 in words is "one trillion, two hundred twenty-one million, one hundred one thousand, two hundred twenty-one".