21220220221111 has 4 divisors (see below), whose sum is σ = 21220462667592. Its totient is φ = 21219977774632.

The previous prime is 21220220221097. The next prime is 21220220221121. The reversal of 21220220221111 is 11112202202212.

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 21220220221111 - 2³³ = 21211630286519 is a prime.

It is a super-4 number, since 4×21220220221111⁴ (a number of 54 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220220221121) 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, 121091905 + ... + 121267018.

It is an arithmetic number, because the mean of its divisors is an integer number (5305115666898).

Almost surely, 2^{21220220221111} is an apocalyptic number.

21220220221111 is a deficient number, since it is larger than the sum of its proper divisors (242446481).

21220220221111 is an equidigital number, since it uses as much as digits as its factorization.

21220220221111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242446480.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21220220221111 its reverse (11112202202212), we get a palindrome (32332422423323).

The spelling of 21220220221111 in words is "twenty-one trillion, two hundred twenty billion, two hundred twenty million, two hundred twenty-one thousand, one hundred eleven".