22001021221221 has 80 divisors (see below), whose sum is σ = 38188235937280. Its totient is φ = 12362669051040.

The previous prime is 22001021221169. The next prime is 22001021221229. The reversal of 22001021221221 is 12212212010022.

It is a happy number.

22001021221221 is a `hidden beast` number, since 2 + 200 + 1 + 0 + 21 + 221 + 221 = 666.

It is not a de Polignac number, because 22001021221221 - 2¹⁰ = 22001021220197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 22001021221194 and 22001021221203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22001021221229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 21184590 + ... + 22198848.

It is an arithmetic number, because the mean of its divisors is an integer number (477352949216).

Almost surely, 2^{22001021221221} is an apocalyptic number.

22001021221221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

22001021221221 is a deficient number, since it is larger than the sum of its proper divisors (16187214716059).

22001021221221 is a wasteful number, since it uses less digits than its factorization.

22001021221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1014916 (or 1014907 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 22001021221221 its reverse (12212212010022), we get a palindrome (34213233231243).

The spelling of 22001021221221 in words is "twenty-two trillion, one billion, twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".