123221221 has 2 divisors, whose sum is σ = 123221222. Its totient is φ = 123221220.

The previous prime is 123221191. The next prime is 123221291. The reversal of 123221221 is 122122321.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85840225 + 37380996 = 9265^2 + 6114^2 .

It is a cyclic number.

It is not a de Polignac number, because 123221221 - 2¹⁹ = 122696933 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 123221195 and 123221204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123221291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61610610 + 61610611.

It is an arithmetic number, because the mean of its divisors is an integer number (61610611).

Almost surely, 2^123221221 is an apocalyptic number.

It is an amenable number.

123221221 is a deficient number, since it is larger than the sum of its proper divisors (1).

123221221 is an equidigital number, since it uses as much as digits as its factorization.

123221221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96, while the sum is 16.

The square root of 123221221 is about 11100.5054389429. The cubic root of 123221221 is about 497.6169549029.

Adding to 123221221 its reverse (122122321), we get a palindrome (245343542).

The spelling of 123221221 in words is "one hundred twenty-three million, two hundred twenty-one thousand, two hundred twenty-one".