221221210212121 has 8 divisors (see below), whose sum is σ = 253054709020800. Its totient is φ = 189445328598048.

The previous prime is 221221210212077. The next prime is 221221210212127. The reversal of 221221210212121 is 121212012122122.

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

It is a cyclic number.

It is not a de Polignac number, because 221221210212121 - 2²⁷ = 221221075994393 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221221210212092 and 221221210212101.

It is not an unprimeable number, because it can be changed into a prime (221221210212127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14404290421 + ... + 14404305778.

It is an arithmetic number, because the mean of its divisors is an integer number (31631838627600).

Almost surely, 2^{221221210212121} is an apocalyptic number.

It is an amenable number.

221221210212121 is a deficient number, since it is larger than the sum of its proper divisors (31833498808679).

221221210212121 is a wasteful number, since it uses less digits than its factorization.

221221210212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28808597303.

The product of its (nonzero) digits is 256, while the sum is 22.

Adding to 221221210212121 its reverse (121212012122122), we get a palindrome (342433222334243).

The spelling of 221221210212121 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, two hundred ten million, two hundred twelve thousand, one hundred twenty-one".