221543212 has 12 divisors (see below), whose sum is σ = 422946216. Its totient is φ = 100701440.

The previous prime is 221543159. The next prime is 221543219. The reversal of 221543212 is 212345122.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (221543219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2517493 + ... + 2517580.

It is an arithmetic number, because the mean of its divisors is an integer number (35245518).

Almost surely, 2^221543212 is an apocalyptic number.

221543212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

221543212 is a deficient number, since it is larger than the sum of its proper divisors (201403004).

221543212 is a wasteful number, since it uses less digits than its factorization.

221543212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5035088 (or 5035086 counting only the distinct ones).

The product of its digits is 960, while the sum is 22.

The square root of 221543212 is about 14884.3277308718. The cubic root of 221543212 is about 605.0893131356.

Adding to 221543212 its reverse (212345122), we get a palindrome (433888334).

The spelling of 221543212 in words is "two hundred twenty-one million, five hundred forty-three thousand, two hundred twelve".