221231312 has 20 divisors (see below), whose sum is σ = 428886240. Its totient is φ = 110551008.

The previous prime is 221231293. The next prime is 221231321. The reversal of 221231312 is 213132122.

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, 36533 + ... + 42155.

It is an arithmetic number, because the mean of its divisors is an integer number (21444312).

Almost surely, 2^221231312 is an apocalyptic number.

It is an amenable number.

221231312 is a deficient number, since it is larger than the sum of its proper divisors (207654928).

221231312 is a wasteful number, since it uses less digits than its factorization.

221231312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8090 (or 8084 counting only the distinct ones).

The product of its digits is 144, while the sum is 17.

The square root of 221231312 is about 14873.8465771299. The cubic root of 221231312 is about 604.8052210900.

Adding to 221231312 its reverse (213132122), we get a palindrome (434363434).

The spelling of 221231312 in words is "two hundred twenty-one million, two hundred thirty-one thousand, three hundred twelve".