23221212221 has 4 divisors (see below), whose sum is σ = 23307536700. Its totient is φ = 23134887744.

The previous prime is 23221212199. The next prime is 23221212227. The reversal of 23221212221 is 12221212232.

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 9947868121 + 13273344100 = 99739^2 + 115210^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23221212221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 23221212193 and 23221212202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23221212227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43161836 + ... + 43162373.

It is an arithmetic number, because the mean of its divisors is an integer number (5826884175).

Almost surely, 2^23221212221 is an apocalyptic number.

It is an amenable number.

23221212221 is a deficient number, since it is larger than the sum of its proper divisors (86324479).

23221212221 is an equidigital number, since it uses as much as digits as its factorization.

23221212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86324478.

The product of its digits is 384, while the sum is 20.

Adding to 23221212221 its reverse (12221212232), we get a palindrome (35442424453).

The spelling of 23221212221 in words is "twenty-three billion, two hundred twenty-one million, two hundred twelve thousand, two hundred twenty-one".