221131312 has 20 divisors (see below), whose sum is σ = 429723736. Its totient is φ = 110234880.

The previous prime is 221131307. The next prime is 221131321. The reversal of 221131312 is 213131122.

221131312 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (16).

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, 15114 + ... + 25897.

Almost surely, 2^221131312 is an apocalyptic number.

It is an amenable number.

221131312 is a deficient number, since it is larger than the sum of its proper divisors (208592424).

221131312 is a wasteful number, since it uses less digits than its factorization.

221131312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41356 (or 41350 counting only the distinct ones).

The product of its digits is 72, while the sum is 16.

The square root of 221131312 is about 14870.4845919694. The cubic root of 221131312 is about 604.7140802285.

Adding to 221131312 its reverse (213131122), we get a palindrome (434262434).

The spelling of 221131312 in words is "two hundred twenty-one million, one hundred thirty-one thousand, three hundred twelve".