321220121 has 4 divisors (see below), whose sum is σ = 327280932. Its totient is φ = 315159312.

The previous prime is 321220103. The next prime is 321220147. The reversal of 321220121 is 121022123.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 121022123 = 131 ⋅923833.

It can be written as a sum of positive squares in 2 ways, for example, as 274366096 + 46854025 = 16564^2 + 6845^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-321220121 is a prime.

It is a super-2 number, since 2×321220121² = 206364732270509282, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 321220096 and 321220105.

It is not an unprimeable number, because it can be changed into a prime (321220021) 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, 3030326 + ... + 3030431.

It is an arithmetic number, because the mean of its divisors is an integer number (81820233).

Almost surely, 2^321220121 is an apocalyptic number.

It is an amenable number.

321220121 is a deficient number, since it is larger than the sum of its proper divisors (6060811).

321220121 is an equidigital number, since it uses as much as digits as its factorization.

321220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6060810.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 321220121 is about 17922.6147924905. The cubic root of 321220121 is about 684.8586001139.

Adding to 321220121 its reverse (121022123), we get a palindrome (442242244).

The spelling of 321220121 in words is "three hundred twenty-one million, two hundred twenty thousand, one hundred twenty-one".