321312220 has 12 divisors (see below), whose sum is σ = 674755704. Its totient is φ = 128524880.

The previous prime is 321312191. The next prime is 321312247. The reversal of 321312220 is 22213123.

It is a junction number, because it is equal to n+sod(n) for n = 321312194 and 321312203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8032786 + ... + 8032825.

It is an arithmetic number, because the mean of its divisors is an integer number (56229642).

Almost surely, 2^321312220 is an apocalyptic number.

It is an amenable number.

321312220 is an abundant number, since it is smaller than the sum of its proper divisors (353443484).

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

321312220 is a wasteful number, since it uses less digits than its factorization.

321312220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16065620 (or 16065618 counting only the distinct ones).

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

The square root of 321312220 is about 17925.1839600044. The cubic root of 321312220 is about 684.9240472023.

Adding to 321312220 its reverse (22213123), we get a palindrome (343525343).

The spelling of 321312220 in words is "three hundred twenty-one million, three hundred twelve thousand, two hundred twenty".