1001221020221 has 2 divisors, whose sum is σ = 1001221020222. Its totient is φ = 1001221020220.

The previous prime is 1001221020209. The next prime is 1001221020271. The reversal of 1001221020221 is 1220201221001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 568764847225 + 432456172996 = 754165^2 + 657614^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001221020221 - 2²⁶ = 1001153911357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1001221020196 and 1001221020205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1001221020271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 500610510110 + 500610510111.

It is an arithmetic number, because the mean of its divisors is an integer number (500610510111).

Almost surely, 2^{1001221020221} is an apocalyptic number.

It is an amenable number.

1001221020221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1001221020221 is an equidigital number, since it uses as much as digits as its factorization.

1001221020221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 1001221020221 its reverse (1220201221001), we get a palindrome (2221422241222).

The spelling of 1001221020221 in words is "one trillion, one billion, two hundred twenty-one million, twenty thousand, two hundred twenty-one".