221220122222021 has 4 divisors (see below), whose sum is σ = 238237054700652. Its totient is φ = 204203189743392.

The previous prime is 221220122222003. The next prime is 221220122222059. The reversal of 221220122222021 is 120222221022122.

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 70091823991396 + 151128298230625 = 8372086^2 + 12293425^2 .

It is a cyclic number.

It is not a de Polignac number, because 221220122222021 - 2⁶ = 221220122221957 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 (221220122222921) 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, 8508466239296 + ... + 8508466239321.

It is an arithmetic number, because the mean of its divisors is an integer number (59559263675163).

Almost surely, 2^{221220122222021} is an apocalyptic number.

It is an amenable number.

221220122222021 is a deficient number, since it is larger than the sum of its proper divisors (17016932478631).

221220122222021 is a wasteful number, since it uses less digits than its factorization.

221220122222021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17016932478630.

The product of its (nonzero) digits is 1024, while the sum is 23.

Adding to 221220122222021 its reverse (120222221022122), we get a palindrome (341442343244143).

The spelling of 221220122222021 in words is "two hundred twenty-one trillion, two hundred twenty billion, one hundred twenty-two million, two hundred twenty-two thousand, twenty-one".