221031312 has 40 divisors (see below), whose sum is σ = 574010880. Its totient is φ = 73288320.

The previous prime is 221031257. The next prime is 221031323. The reversal of 221031312 is 213130122.

It is a junction number, because it is equal to n+sod(n) for n = 221031291 and 221031300.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2887 + ... + 21222.

It is an arithmetic number, because the mean of its divisors is an integer number (14350272).

Almost surely, 2^221031312 is an apocalyptic number.

It is an amenable number.

221031312 is an abundant number, since it is smaller than the sum of its proper divisors (352979568).

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

221031312 is a wasteful number, since it uses less digits than its factorization.

221031312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24311 (or 24305 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

The square root of 221031312 is about 14867.1218465445. The cubic root of 221031312 is about 604.6229118857.

Adding to 221031312 its reverse (213130122), we get a palindrome (434161434).

The spelling of 221031312 in words is "two hundred twenty-one million, thirty-one thousand, three hundred twelve".