123213221 has 4 divisors (see below), whose sum is σ = 123751500. Its totient is φ = 122674944.

The previous prime is 123213203. The next prime is 123213247. The reversal of 123213221 is 122312321.

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 48580900 + 74632321 = 6970^2 + 8639^2 .

It is a cyclic number.

It is not a de Polignac number, because 123213221 - 2²² = 119018917 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 123213221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123213281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 268796 + ... + 269253.

It is an arithmetic number, because the mean of its divisors is an integer number (30937875).

Almost surely, 2^123213221 is an apocalyptic number.

It is an amenable number.

123213221 is a deficient number, since it is larger than the sum of its proper divisors (538279).

123213221 is an equidigital number, since it uses as much as digits as its factorization.

123213221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538278.

The product of its digits is 144, while the sum is 17.

The square root of 123213221 is about 11100.1450891419. The cubic root of 123213221 is about 497.6061855950.

Adding to 123213221 its reverse (122312321), we get a palindrome (245525542).

The spelling of 123213221 in words is "one hundred twenty-three million, two hundred thirteen thousand, two hundred twenty-one".