23220021221 has 4 divisors (see below), whose sum is σ = 23786363244. Its totient is φ = 22653679200.

The previous prime is 23220021211. The next prime is 23220021229. The reversal of 23220021221 is 12212002232.

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 1784133121 + 21435888100 = 42239^2 + 146410^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23220021221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 23220021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23220021229) 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, 283170950 + ... + 283171031.

It is an arithmetic number, because the mean of its divisors is an integer number (5946590811).

Almost surely, 2^23220021221 is an apocalyptic number.

It is an amenable number.

23220021221 is a deficient number, since it is larger than the sum of its proper divisors (566342023).

23220021221 is an equidigital number, since it uses as much as digits as its factorization.

23220021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 566342022.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 23220021221 its reverse (12212002232), we get a palindrome (35432023453).

The spelling of 23220021221 in words is "twenty-three billion, two hundred twenty million, twenty-one thousand, two hundred twenty-one".