221002022020121 has 4 divisors (see below), whose sum is σ = 221009175840612. Its totient is φ = 220994868199632.

The previous prime is 221002022020111. The next prime is 221002022020133. The reversal of 221002022020121 is 121020220200122.

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 89092455654400 + 131909566365721 = 9438880^2 + 11485189^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221002022020121 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 221002022020121.

It is not an unprimeable number, because it can be changed into a prime (221002022020111) 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, 3576863906 + ... + 3576925691.

It is an arithmetic number, because the mean of its divisors is an integer number (55252293960153).

Almost surely, 2^{221002022020121} is an apocalyptic number.

It is an amenable number.

221002022020121 is a deficient number, since it is larger than the sum of its proper divisors (7153820491).

221002022020121 is an equidigital number, since it uses as much as digits as its factorization.

221002022020121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7153820490.

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

Adding to 221002022020121 its reverse (121020220200122), we get a palindrome (342022242220243).

The spelling of 221002022020121 in words is "two hundred twenty-one trillion, two billion, twenty-two million, twenty thousand, one hundred twenty-one".