20211222111221 has 8 divisors (see below), whose sum is σ = 20219531548824. Its totient is φ = 20202913543680.

The previous prime is 20211222111209. The next prime is 20211222111233. The reversal of 20211222111221 is 12211122211202.

It is an interprime number because it is at equal distance from previous prime (20211222111209) and next prime (20211222111233).

It can be written as a sum of positive squares in 4 ways, for example, as 4926797290321 + 15284424820900 = 2219639^2 + 3909530^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20211222111221 - 2²² = 20211217916917 is a prime.

It is a super-2 number, since 2×20211222111221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20211222111193 and 20211222111202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20211222114221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48478571 + ... + 48893703.

It is an arithmetic number, because the mean of its divisors is an integer number (2527441443603).

Almost surely, 2^{20211222111221} is an apocalyptic number.

It is an amenable number.

20211222111221 is a deficient number, since it is larger than the sum of its proper divisors (8309437603).

20211222111221 is a wasteful number, since it uses less digits than its factorization.

20211222111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435031.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 20211222111221 its reverse (12211122211202), we get a palindrome (32422344322423).

The spelling of 20211222111221 in words is "twenty trillion, two hundred eleven billion, two hundred twenty-two million, one hundred eleven thousand, two hundred twenty-one".