321213220 has 12 divisors (see below), whose sum is σ = 674547804. Its totient is φ = 128485280.

The previous prime is 321213203. The next prime is 321213223. The reversal of 321213220 is 22312123.

It can be written as a sum of positive squares in 2 ways, for example, as 161645796 + 159567424 = 12714^2 + 12632^2 .

It is a junction number, because it is equal to n+sod(n) for n = 321213194 and 321213203.

It is not an unprimeable number, because it can be changed into a prime (321213223) 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, 8030311 + ... + 8030350.

It is an arithmetic number, because the mean of its divisors is an integer number (56212317).

Almost surely, 2^321213220 is an apocalyptic number.

It is an amenable number.

321213220 is an abundant number, since it is smaller than the sum of its proper divisors (353334584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

321213220 is a wasteful number, since it uses less digits than its factorization.

321213220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16060670 (or 16060668 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 321213220 is about 17922.4222693251. The cubic root of 321213220 is about 684.8536956442.

Adding to 321213220 its reverse (22312123), we get a palindrome (343525343).

The spelling of 321213220 in words is "three hundred twenty-one million, two hundred thirteen thousand, two hundred twenty".