20021201222221 has 4 divisors (see below), whose sum is σ = 20153791958944. Its totient is φ = 19888610485500.

The previous prime is 20021201222161. The next prime is 20021201222237. The reversal of 20021201222221 is 12222210212002.

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 20021201222221 - 2⁹ = 20021201221709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021201222291) 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, 66295368135 + ... + 66295368436.

It is an arithmetic number, because the mean of its divisors is an integer number (5038447989736).

Almost surely, 2^{20021201222221} is an apocalyptic number.

It is an amenable number.

20021201222221 is a deficient number, since it is larger than the sum of its proper divisors (132590736723).

20021201222221 is a wasteful number, since it uses less digits than its factorization.

20021201222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132590736722.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 20021201222221 its reverse (12222210212002), we get a palindrome (32243411434223).

The spelling of 20021201222221 in words is "twenty trillion, twenty-one billion, two hundred one million, two hundred twenty-two thousand, two hundred twenty-one".