312221320 has 64 divisors (see below), whose sum is σ = 776200320. Its totient is φ = 112425984.

The previous prime is 312221317. The next prime is 312221321. The reversal of 312221320 is 23122213.

It is a junction number, because it is equal to n+sod(n) for n = 312221294 and 312221303.

It is not an unprimeable number, because it can be changed into a prime (312221321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5659 + ... + 25621.

It is an arithmetic number, because the mean of its divisors is an integer number (12128130).

Almost surely, 2^312221320 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 312221320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (388100160).

312221320 is an abundant number, since it is smaller than the sum of its proper divisors (463979000).

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

312221320 is a wasteful number, since it uses less digits than its factorization.

312221320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20014 (or 20010 counting only the distinct ones).

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

The square root of 312221320 is about 17669.7855108657. The cubic root of 312221320 is about 678.4026231153.

Adding to 312221320 its reverse (23122213), we get a palindrome (335343533).

It can be divided in two parts, 3122 and 21320, that added together give a palindrome (24442).

The spelling of 312221320 in words is "three hundred twelve million, two hundred twenty-one thousand, three hundred twenty".