221511242 has 8 divisors (see below), whose sum is σ = 333718500. Its totient is φ = 110271744.

The previous prime is 221511209. The next prime is 221511259. The reversal of 221511242 is 242115122.

It can be written as a sum of positive squares in 2 ways, for example, as 221444161 + 67081 = 14881^2 + 259^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241367 + ... + 242282.

Almost surely, 2^221511242 is an apocalyptic number.

221511242 is a deficient number, since it is larger than the sum of its proper divisors (112207258).

221511242 is a wasteful number, since it uses less digits than its factorization.

221511242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483880.

The product of its digits is 320, while the sum is 20.

The square root of 221511242 is about 14883.2537437215. The cubic root of 221511242 is about 605.0602057427.

Adding to 221511242 its reverse (242115122), we get a palindrome (463626364).

The spelling of 221511242 in words is "two hundred twenty-one million, five hundred eleven thousand, two hundred forty-two".