221220132212021 has 4 divisors (see below), whose sum is σ = 226615745192844. Its totient is φ = 215824519231200.

The previous prime is 221220132212017. The next prime is 221220132212039. The reversal of 221220132212021 is 120212231022122.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11279448363121 + 209940683848900 = 3358489^2 + 14489330^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220132212021 - 2² = 221220132212017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220132211021) 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, 2697806490350 + ... + 2697806490431.

It is an arithmetic number, because the mean of its divisors is an integer number (56653936298211).

Almost surely, 2^{221220132212021} is an apocalyptic number.

It is an amenable number.

221220132212021 is a deficient number, since it is larger than the sum of its proper divisors (5395612980823).

221220132212021 is an equidigital number, since it uses as much as digits as its factorization.

221220132212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5395612980822.

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 221220132212021 its reverse (120212231022122), we get a palindrome (341432363234143).

The spelling of 221220132212021 in words is "two hundred twenty-one trillion, two hundred twenty billion, one hundred thirty-two million, two hundred twelve thousand, twenty-one".