221221020212 has 6 divisors (see below), whose sum is σ = 387136785378. Its totient is φ = 110610510104.

The previous prime is 221221020211. The next prime is 221221020253. The reversal of 221221020212 is 212020122122.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 121665625636 + 99555394576 = 348806^2 + 315524^2 .

It is a super-2 number, since 2×221221020212² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221020211) 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 as a sum of consecutive naturals, namely, 27652627523 + ... + 27652627530.

It is an arithmetic number, because the mean of its divisors is an integer number (64522797563).

Almost surely, 2^221221020212 is an apocalyptic number.

It is an amenable number.

221221020212 is a deficient number, since it is larger than the sum of its proper divisors (165915765166).

221221020212 is a wasteful number, since it uses less digits than its factorization.

221221020212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55305255057 (or 55305255055 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 221221020212 its reverse (212020122122), we get a palindrome (433241142334).

The spelling of 221221020212 in words is "two hundred twenty-one billion, two hundred twenty-one million, twenty thousand, two hundred twelve".