1001221002121 has 2 divisors, whose sum is σ = 1001221002122. Its totient is φ = 1001221002120.

The previous prime is 1001221001993. The next prime is 1001221002127. The reversal of 1001221002121 is 1212001221001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1000880193600 + 340808521 = 1000440^2 + 18461^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001221002121 - 2⁷ = 1001221001993 is a prime.

It is not a weakly prime, because it can be changed into another prime (1001221002127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500610501060 + 500610501061.

It is an arithmetic number, because the mean of its divisors is an integer number (500610501061).

Almost surely, 2^{1001221002121} is an apocalyptic number.

It is an amenable number.

1001221002121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001221002121 is an equidigital number, since it uses as much as digits as its factorization.

1001221002121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1001221002121 its reverse (1212001221001), we get a palindrome (2213222223122).

The spelling of 1001221002121 in words is "one trillion, one billion, two hundred twenty-one million, two thousand, one hundred twenty-one".