221001020022221 has 4 divisors (see below), whose sum is σ = 225170850588732. Its totient is φ = 216831189455712.

The previous prime is 221001020022197. The next prime is 221001020022227. The reversal of 221001020022221 is 122220020100122.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 99104294752996 + 121896725269225 = 9955114^2 + 11040685^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221001020022221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221001020022221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221001020022227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2084915283176 + ... + 2084915283281.

It is an arithmetic number, because the mean of its divisors is an integer number (56292712647183).

Almost surely, 2^{221001020022221} is an apocalyptic number.

It is an amenable number.

221001020022221 is a deficient number, since it is larger than the sum of its proper divisors (4169830566511).

221001020022221 is an equidigital number, since it uses as much as digits as its factorization.

221001020022221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4169830566510.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 221001020022221 its reverse (122220020100122), we get a palindrome (343221040122343).

The spelling of 221001020022221 in words is "two hundred twenty-one trillion, one billion, twenty million, twenty-two thousand, two hundred twenty-one".