221212203221 has 8 divisors (see below), whose sum is σ = 226828362264. Its totient is φ = 215660229120.

The previous prime is 221212203131. The next prime is 221212203229. The reversal of 221212203221 is 122302212122.

It can be written as a sum of positive squares in 4 ways, for example, as 1475328100 + 219736875121 = 38410^2 + 468761^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221212203221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221212203193 and 221212203202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221212203229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16039256 + ... + 16053041.

It is an arithmetic number, because the mean of its divisors is an integer number (28353545283).

Almost surely, 2^221212203221 is an apocalyptic number.

It is an amenable number.

221212203221 is a deficient number, since it is larger than the sum of its proper divisors (5616159043).

221212203221 is a wasteful number, since it uses less digits than its factorization.

221212203221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32092471.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 221212203221 its reverse (122302212122), we get a palindrome (343514415343).

The spelling of 221212203221 in words is "two hundred twenty-one billion, two hundred twelve million, two hundred three thousand, two hundred twenty-one".