221221222221021 has 32 divisors (see below), whose sum is σ = 338727923297280. Its totient is φ = 127010968156800.

The previous prime is 221221222220903. The next prime is 221221222221073. The reversal of 221221222221021 is 120122222122122.

It is a happy number.

It is not a de Polignac number, because 221221222221021 - 2¹¹ = 221221222218973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221221222220982 and 221221222221000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221222225021) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4961881 + ... + 21611633.

It is an arithmetic number, because the mean of its divisors is an integer number (10585247603040).

Almost surely, 2^{221221222221021} is an apocalyptic number.

It is an amenable number.

221221222221021 is a deficient number, since it is larger than the sum of its proper divisors (117506701076259).

221221222221021 is a wasteful number, since it uses less digits than its factorization.

221221222221021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16670977.

The product of its (nonzero) digits is 1024, while the sum is 24.

Adding to 221221222221021 its reverse (120122222122122), we get a palindrome (341343444343143).

The spelling of 221221222221021 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, two hundred twenty-two million, two hundred twenty-one thousand, twenty-one".