210121200011221 has 8 divisors (see below), whose sum is σ = 211982041660824. Its totient is φ = 208260382256640.

The previous prime is 210121200011213. The next prime is 210121200011263. The reversal of 210121200011221 is 122110002121012.

It can be written as a sum of positive squares in 4 ways, for example, as 59933454388900 + 150187745622321 = 7741670^2 + 12255111^2 .

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 210121200011221 - 2³ = 210121200011213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 210121200011195 and 210121200011204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210121200011201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11927635 + ... + 23717311.

It is an arithmetic number, because the mean of its divisors is an integer number (26497755207603).

Almost surely, 2^{210121200011221} is an apocalyptic number.

It is an amenable number.

210121200011221 is a deficient number, since it is larger than the sum of its proper divisors (1860841649603).

210121200011221 is a wasteful number, since it uses less digits than its factorization.

210121200011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11947511.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 210121200011221 its reverse (122110002121012), we get a palindrome (332231202132233).

The spelling of 210121200011221 in words is "two hundred ten trillion, one hundred twenty-one billion, two hundred million, eleven thousand, two hundred twenty-one".