10212121221 has 16 divisors (see below), whose sum is σ = 14423194368. Its totient is φ = 6404902400.

The previous prime is 10212121217. The next prime is 10212121223. The reversal of 10212121221 is 12212121201.

It is a cyclic number.

It is not a de Polignac number, because 10212121221 - 2² = 10212121217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 10212121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10212121223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83476 + ... + 165506.

It is an arithmetic number, because the mean of its divisors is an integer number (901449648).

Almost surely, 2^10212121221 is an apocalyptic number.

It is an amenable number.

10212121221 is a deficient number, since it is larger than the sum of its proper divisors (4211073147).

10212121221 is a wasteful number, since it uses less digits than its factorization.

10212121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84492.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 10212121221 its reverse (12212121201), we get a palindrome (22424242422).

The spelling of 10212121221 in words is "ten billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".