221001221021021 has 12 divisors (see below), whose sum is σ = 257598249552000. Its totient is φ = 189049999524120.

The previous prime is 221001221020969. The next prime is 221001221021029. The reversal of 221001221021021 is 120120122100122.

It is a de Polignac number, because none of the positive numbers 2^k-221001221021021 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221001221021029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4519243085 + ... + 4519291986.

It is an arithmetic number, because the mean of its divisors is an integer number (21466520796000).

Almost surely, 2^{221001221021021} is an apocalyptic number.

It is an amenable number.

221001221021021 is a deficient number, since it is larger than the sum of its proper divisors (36597028530979).

221001221021021 is an equidigital number, since it uses as much as digits as its factorization.

221001221021021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9038535584 (or 9038535577 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221001221021021 its reverse (120120122100122), we get a palindrome (341121343121143).

The spelling of 221001221021021 in words is "two hundred twenty-one trillion, one billion, two hundred twenty-one million, twenty-one thousand, twenty-one".