221021102212121 has 4 divisors (see below), whose sum is σ = 223166938156032. Its totient is φ = 218875266268212.

The previous prime is 221021102212087. The next prime is 221021102212151. The reversal of 221021102212121 is 121212201120122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221021102212121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221021102212093 and 221021102212102.

It is not an unprimeable number, because it can be changed into a prime (221021102212151) 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 3 ways as a sum of consecutive naturals, for example, 1072917971801 + ... + 1072917972006.

It is an arithmetic number, because the mean of its divisors is an integer number (55791734539008).

Almost surely, 2^{221021102212121} is an apocalyptic number.

It is an amenable number.

221021102212121 is a deficient number, since it is larger than the sum of its proper divisors (2145835943911).

221021102212121 is a wasteful number, since it uses less digits than its factorization.

221021102212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2145835943910.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 221021102212121 its reverse (121212201120122), we get a palindrome (342233303332243).

The spelling of 221021102212121 in words is "two hundred twenty-one trillion, twenty-one billion, one hundred two million, two hundred twelve thousand, one hundred twenty-one".