221230311221 has 4 divisors (see below), whose sum is σ = 223420710444. Its totient is φ = 219039912000.

The previous prime is 221230311173. The next prime is 221230311233. The reversal of 221230311221 is 122113032122.

221230311221 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.

It can be written as a sum of positive squares in 2 ways, for example, as 192707830225 + 28522480996 = 438985^2 + 168886^2 .

It is a de Polignac number, because none of the positive numbers 2^k-221230311221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221230311193 and 221230311202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221230311821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1095199460 + ... + 1095199661.

It is an arithmetic number, because the mean of its divisors is an integer number (55855177611).

Almost surely, 2^221230311221 is an apocalyptic number.

It is an amenable number.

221230311221 is a deficient number, since it is larger than the sum of its proper divisors (2190399223).

221230311221 is a wasteful number, since it uses less digits than its factorization.

221230311221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2190399222.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 221230311221 its reverse (122113032122), we get a palindrome (343343343343).

The spelling of 221230311221 in words is "two hundred twenty-one billion, two hundred thirty million, three hundred eleven thousand, two hundred twenty-one".