212221001221 has 4 divisors (see below), whose sum is σ = 217397123244. Its totient is φ = 207044879200.

The previous prime is 212221001171. The next prime is 212221001231. The reversal of 212221001221 is 122100122212.

It is a happy number.

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 108495136996 + 103725864225 = 329386^2 + 322065^2 .

It is a cyclic number.

It is not a de Polignac number, because 212221001221 - 2¹³ = 212220993029 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212221001195 and 212221001204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212221001231) 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, 2588060950 + ... + 2588061031.

It is an arithmetic number, because the mean of its divisors is an integer number (54349280811).

Almost surely, 2^212221001221 is an apocalyptic number.

It is an amenable number.

212221001221 is a deficient number, since it is larger than the sum of its proper divisors (5176122023).

212221001221 is an equidigital number, since it uses as much as digits as its factorization.

212221001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5176122022.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 212221001221 its reverse (122100122212), we get a palindrome (334321123433).

The spelling of 212221001221 in words is "two hundred twelve billion, two hundred twenty-one million, one thousand, two hundred twenty-one".