221443812 has 18 divisors (see below), whose sum is σ = 559760838. Its totient is φ = 73814592.

The previous prime is 221443801. The next prime is 221443843. The reversal of 221443812 is 218344122.

221443812 is a `hidden beast` number, since 2 + 214 + 438 + 12 = 666.

It can be written as a sum of positive squares in only one way, i.e., 221235876 + 207936 = 14874^2 + 456^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3075573 + ... + 3075644.

Almost surely, 2^221443812 is an apocalyptic number.

It is an amenable number.

221443812 is an abundant number, since it is smaller than the sum of its proper divisors (338317026).

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

221443812 is a wasteful number, since it uses less digits than its factorization.

221443812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6151227 (or 6151222 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 221443812 is about 14880.9882736329. The cubic root of 221443812 is about 604.9988042687.

Adding to 221443812 its reverse (218344122), we get a palindrome (439787934).

The spelling of 221443812 in words is "two hundred twenty-one million, four hundred forty-three thousand, eight hundred twelve".