221220110212121 has 8 divisors (see below), whose sum is σ = 222944451422280. Its totient is φ = 219502363041792.

The previous prime is 221220110212117. The next prime is 221220110212147. The reversal of 221220110212121 is 121212011022122.

It can be written as a sum of positive squares in 4 ways, for example, as 203684417958025 + 17535692254096 = 14271805^2 + 4187564^2 .

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 221220110212121 - 2² = 221220110212117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 221220110212093 and 221220110212102.

It is not an unprimeable number, because it can be changed into a prime (221220110212721) 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, 1648442600 + ... + 1648576793.

It is an arithmetic number, because the mean of its divisors is an integer number (27868056427785).

Almost surely, 2^{221220110212121} is an apocalyptic number.

It is an amenable number.

221220110212121 is a deficient number, since it is larger than the sum of its proper divisors (1724341210159).

221220110212121 is a wasteful number, since it uses less digits than its factorization.

221220110212121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3297019915.

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

Adding to 221220110212121 its reverse (121212011022122), we get a palindrome (342432121234243).

The spelling of 221220110212121 in words is "two hundred twenty-one trillion, two hundred twenty billion, one hundred ten million, two hundred twelve thousand, one hundred twenty-one".