1223123221 has 4 divisors (see below), whose sum is σ = 1223485632. Its totient is φ = 1222760812.

The previous prime is 1223123203. The next prime is 1223123243. The reversal of 1223123221 is 1223213221.

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 1223123221 - 2⁵ = 1223123189 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 (1223123201) 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, 176095 + ... + 182908.

It is an arithmetic number, because the mean of its divisors is an integer number (305871408).

Almost surely, 2^1223123221 is an apocalyptic number.

It is an amenable number.

1223123221 is a deficient number, since it is larger than the sum of its proper divisors (362411).

1223123221 is an equidigital number, since it uses as much as digits as its factorization.

1223123221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362410.

The product of its digits is 288, while the sum is 19.

The square root of 1223123221 is about 34973.1785944601. The cubic root of 1223123221 is about 1069.4407713308.

Adding to 1223123221 its reverse (1223213221), we get a palindrome (2446336442).

Subtracting 1223123221 from its reverse (1223213221), we obtain a square (90000 = 300²).

The spelling of 1223123221 in words is "one billion, two hundred twenty-three million, one hundred twenty-three thousand, two hundred twenty-one".