201221220021221 has 4 divisors (see below), whose sum is σ = 205502522574912. Its totient is φ = 196939917467532.

The previous prime is 201221220021203. The next prime is 201221220021233. The reversal of 201221220021221 is 122120022122102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 201221220021221 - 2²⁶ = 201221152912357 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201221220021193 and 201221220021202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221220021251) 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, 2140651276775 + ... + 2140651276868.

It is an arithmetic number, because the mean of its divisors is an integer number (51375630643728).

Almost surely, 2^{201221220021221} is an apocalyptic number.

It is an amenable number.

201221220021221 is a deficient number, since it is larger than the sum of its proper divisors (4281302553691).

201221220021221 is an equidigital number, since it uses as much as digits as its factorization.

201221220021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4281302553690.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 201221220021221 its reverse (122120022122102), we get a palindrome (323341242143323).

The spelling of 201221220021221 in words is "two hundred one trillion, two hundred twenty-one billion, two hundred twenty million, twenty-one thousand, two hundred twenty-one".