1001122220221 has 4 divisors (see below), whose sum is σ = 1001434196700. Its totient is φ = 1000810243744.

The previous prime is 1001122220183. The next prime is 1001122220309. The reversal of 1001122220221 is 1220222211001.

It is a happy number.

1001122220221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 839264860996 + 161857359225 = 916114^2 + 402315^2 .

It is a cyclic number.

It is not a de Polignac number, because 1001122220221 - 2¹⁵ = 1001122187453 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1001122220195 and 1001122220204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001122220821) 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, 155983426 + ... + 155989843.

It is an arithmetic number, because the mean of its divisors is an integer number (250358549175).

Almost surely, 2^{1001122220221} is an apocalyptic number.

It is an amenable number.

1001122220221 is a deficient number, since it is larger than the sum of its proper divisors (311976479).

1001122220221 is an equidigital number, since it uses as much as digits as its factorization.

1001122220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 311976478.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1001122220221 its reverse (1220222211001), we get a palindrome (2221344431222).

The spelling of 1001122220221 in words is "one trillion, one billion, one hundred twenty-two million, two hundred twenty thousand, two hundred twenty-one".