221210201201221 has 4 divisors (see below), whose sum is σ = 221210413421292. Its totient is φ = 221209988981152.

The previous prime is 221210201201219. The next prime is 221210201201237. The reversal of 221210201201221 is 122102102012122.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 97459839230625 + 123750361970596 = 9872175^2 + 11124314^2 .

It is a cyclic number.

It is not a de Polignac number, because 221210201201221 - 2¹ = 221210201201219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221210201201201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104538736 + ... + 106633801.

It is an arithmetic number, because the mean of its divisors is an integer number (55302603355323).

Almost surely, 2^{221210201201221} is an apocalyptic number.

It is an amenable number.

221210201201221 is a deficient number, since it is larger than the sum of its proper divisors (212220071).

221210201201221 is a wasteful number, since it uses less digits than its factorization.

221210201201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212220070.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 221210201201221 its reverse (122102102012122), we get a palindrome (343312303213343).

The spelling of 221210201201221 in words is "two hundred twenty-one trillion, two hundred ten billion, two hundred one million, two hundred one thousand, two hundred twenty-one".