123221 has 8 divisors (see below), whose sum is σ = 145920. Its totient is φ = 101808.

The previous prime is 123217. The next prime is 123229. The reversal of 123221 is 122321.

123221 = T₃₄ + T₃₅ + ... + T₉₁.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 123221 - 2² = 123217 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 101 + ... + 506.

It is an arithmetic number, because the mean of its divisors is an integer number (18240).

2¹²³²²¹ is an apocalyptic number.

123221 is the 203-rd octagonal number.

It is an amenable number.

123221 is a deficient number, since it is larger than the sum of its proper divisors (22699).

123221 is an equidigital number, since it uses as much as digits as its factorization.

123221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643.

The product of its digits is 24, while the sum is 11.

The square root of 123221 is about 351.0284888723. The cubic root of 123221 is about 49.7616657407.

Adding to 123221 its reverse (122321), we get a palindrome (245542).

Subtracting from 123221 its reverse (122321), we obtain a square (900 = 30²).

The spelling of 123221 in words is "one hundred twenty-three thousand, two hundred twenty-one", and thus it is an iban number.