221221412 has 24 divisors (see below), whose sum is σ = 397083456. Its totient is φ = 107781408.

The previous prime is 221221397. The next prime is 221221421. The reversal of 221221412 is 214122122.

It is a nude number because it is divisible by every one of its digits.

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, 85238 + ... + 87794.

It is an arithmetic number, because the mean of its divisors is an integer number (16545144).

Almost surely, 2^221221412 is an apocalyptic number.

It is an amenable number.

221221412 is a deficient number, since it is larger than the sum of its proper divisors (175862044).

221221412 is a wasteful number, since it uses less digits than its factorization.

221221412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3107 (or 3105 counting only the distinct ones).

The product of its digits is 128, while the sum is 17.

The square root of 221221412 is about 14873.5137744919. The cubic root of 221221412 is about 604.7961993698.

Adding to 221221412 its reverse (214122122), we get a palindrome (435343534).

The spelling of 221221412 in words is "two hundred twenty-one million, two hundred twenty-one thousand, four hundred twelve".