221206066 has 8 divisors (see below), whose sum is σ = 331872300. Its totient is φ = 110581968.

The previous prime is 221206043. The next prime is 221206067. The reversal of 221206066 is 660602122.

It can be written as a sum of positive squares in 2 ways, for example, as 204633025 + 16573041 = 14305^2 + 4071^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 221206066.

It is not an unprimeable number, because it can be changed into a prime (221206067) 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, 14340 + ... + 25456.

Almost surely, 2^221206066 is an apocalyptic number.

221206066 is a deficient number, since it is larger than the sum of its proper divisors (110666234).

221206066 is a wasteful number, since it uses less digits than its factorization.

221206066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21068.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 221206066 is about 14872.9978820680. The cubic root of 221206066 is about 604.7822142602.

Adding to 221206066 its reverse (660602122), we get a palindrome (881808188).

The spelling of 221206066 in words is "two hundred twenty-one million, two hundred six thousand, sixty-six".