23121233221 has 4 divisors (see below), whose sum is σ = 23124807244. Its totient is φ = 23117659200.

The previous prime is 23121233203. The next prime is 23121233237. The reversal of 23121233221 is 12233212132.

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 9237324321 + 13883908900 = 96111^2 + 117830^2 .

It is a cyclic number.

It is not a de Polignac number, because 23121233221 - 2⁵ = 23121233189 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 23121233192 and 23121233201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23121233321) 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, 1777290 + ... + 1790251.

It is an arithmetic number, because the mean of its divisors is an integer number (5781201811).

Almost surely, 2^23121233221 is an apocalyptic number.

It is an amenable number.

23121233221 is a deficient number, since it is larger than the sum of its proper divisors (3574023).

23121233221 is an equidigital number, since it uses as much as digits as its factorization.

23121233221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3574022.

The product of its digits is 864, while the sum is 22.

Adding to 23121233221 its reverse (12233212132), we get a palindrome (35354445353).

The spelling of 23121233221 in words is "twenty-three billion, one hundred twenty-one million, two hundred thirty-three thousand, two hundred twenty-one".