221121213123221 has 4 divisors (see below), whose sum is σ = 221194650925344. Its totient is φ = 221047775321100.

The previous prime is 221121213123199. The next prime is 221121213123299. The reversal of 221121213123221 is 122321312121122.

221121213123221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221121213123221 - 2¹⁰ = 221121213122197 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 (221121213125221) 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, 36718896545 + ... + 36718902566.

It is an arithmetic number, because the mean of its divisors is an integer number (55298662731336).

Almost surely, 2^{221121213123221} is an apocalyptic number.

It is an amenable number.

221121213123221 is a deficient number, since it is larger than the sum of its proper divisors (73437802123).

221121213123221 is an equidigital number, since it uses as much as digits as its factorization.

221121213123221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73437802122.

The product of its digits is 1152, while the sum is 26.

Adding to 221121213123221 its reverse (122321312121122), we get a palindrome (343442525244343).

The spelling of 221121213123221 in words is "two hundred twenty-one trillion, one hundred twenty-one billion, two hundred thirteen million, one hundred twenty-three thousand, two hundred twenty-one".