20021220221111 has 4 divisors (see below), whose sum is σ = 20040489924000. Its totient is φ = 20001950518224.

The previous prime is 20021220221059. The next prime is 20021220221113. The reversal of 20021220221111 is 11112202212002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20021220221111 - 2³⁴ = 20004040351927 is a prime.

It is a super-4 number, since 4×20021220221111⁴ (a number of 54 digits) contains 4444 as substring.

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 20021220221111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021220221113) 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, 9634849886 + ... + 9634851963.

It is an arithmetic number, because the mean of its divisors is an integer number (5010122481000).

Almost surely, 2^{20021220221111} is an apocalyptic number.

20021220221111 is a deficient number, since it is larger than the sum of its proper divisors (19269702889).

20021220221111 is a wasteful number, since it uses less digits than its factorization.

20021220221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19269702888.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 20021220221111 its reverse (11112202212002), we get a palindrome (31133422433113).

The spelling of 20021220221111 in words is "twenty trillion, twenty-one billion, two hundred twenty million, two hundred twenty-one thousand, one hundred eleven".