221021122121 has 8 divisors (see below), whose sum is σ = 224473226688. Its totient is φ = 217578438000.

The previous prime is 221021122079. The next prime is 221021122129. The reversal of 221021122121 is 121221120122.

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-221021122121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221021122121.

It is not an unprimeable number, because it can be changed into a prime (221021122129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2307815 + ... + 2401676.

It is an arithmetic number, because the mean of its divisors is an integer number (28059153336).

Almost surely, 2^221021122121 is an apocalyptic number.

It is an amenable number.

221021122121 is a deficient number, since it is larger than the sum of its proper divisors (3452104567).

221021122121 is an equidigital number, since it uses as much as digits as its factorization.

221021122121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4710223.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 221021122121 its reverse (121221120122), we get a palindrome (342242242243).

The spelling of 221021122121 in words is "two hundred twenty-one billion, twenty-one million, one hundred twenty-two thousand, one hundred twenty-one".