222121222100221 has 4 divisors (see below), whose sum is σ = 222121266821244. Its totient is φ = 222121177379200.

The previous prime is 222121222100209. The next prime is 222121222100251. The reversal of 222121222100221 is 122001222121222.

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 26513333792100 + 195607888308121 = 5149110^2 + 13985989^2 .

It is a cyclic number.

It is not a de Polignac number, because 222121222100221 - 2¹⁷ = 222121221969149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 222121222100192 and 222121222100201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222121222100251) 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, 13823950 + ... + 25206031.

It is an arithmetic number, because the mean of its divisors is an integer number (55530316705311).

Almost surely, 2^{222121222100221} is an apocalyptic number.

It is an amenable number.

222121222100221 is a deficient number, since it is larger than the sum of its proper divisors (44721023).

222121222100221 is an equidigital number, since it uses as much as digits as its factorization.

222121222100221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44721022.

The product of its (nonzero) digits is 512, while the sum is 22.

Adding to 222121222100221 its reverse (122001222121222), we get a palindrome (344122444221443).

The spelling of 222121222100221 in words is "two hundred twenty-two trillion, one hundred twenty-one billion, two hundred twenty-two million, one hundred thousand, two hundred twenty-one".