123212221 has 4 divisors (see below), whose sum is σ = 134413344. Its totient is φ = 112011100.

The previous prime is 123212161. The next prime is 123212233. The reversal of 123212221 is 122212321.

It is a happy number.

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 123212221 - 2¹⁷ = 123081149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 123212195 and 123212204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123212281) 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, 5600545 + ... + 5600566.

It is an arithmetic number, because the mean of its divisors is an integer number (33603336).

Almost surely, 2^123212221 is an apocalyptic number.

123212221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

123212221 is a deficient number, since it is larger than the sum of its proper divisors (11201123).

123212221 is a wasteful number, since it uses less digits than its factorization.

123212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11201122.

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

The square root of 123212221 is about 11100.1000445942. The cubic root of 123212221 is about 497.6048393988.

Adding to 123212221 its reverse (122212321), we get a palindrome (245424542).

The spelling of 123212221 in words is "one hundred twenty-three million, two hundred twelve thousand, two hundred twenty-one".