221643650 has 12 divisors (see below), whose sum is σ = 412257282. Its totient is φ = 88657440.

The previous prime is 221643649. The next prime is 221643661. The reversal of 221643650 is 56346122.

221643650 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 112169281 + 109474369 = 10591^2 + 10463^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2216387 + ... + 2216486.

Almost surely, 2^221643650 is an apocalyptic number.

221643650 is a deficient number, since it is larger than the sum of its proper divisors (190613632).

221643650 is a wasteful number, since it uses less digits than its factorization.

221643650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4432885 (or 4432880 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 221643650 is about 14887.7013000664. The cubic root of 221643650 is about 605.1807396615.

Adding to 221643650 its reverse (56346122), we get a palindrome (277989772).

The spelling of 221643650 in words is "two hundred twenty-one million, six hundred forty-three thousand, six hundred fifty".