221788136 has 32 divisors (see below), whose sum is σ = 430272000. Its totient is φ = 107065920.

The previous prime is 221788129. The next prime is 221788153. The reversal of 221788136 is 631887122.

It is a self number, because there is not a number n which added to its sum of digits gives 221788136.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 147806 + ... + 149298.

It is an arithmetic number, because the mean of its divisors is an integer number (13446000).

Almost surely, 2^221788136 is an apocalyptic number.

It is an amenable number.

221788136 is a deficient number, since it is larger than the sum of its proper divisors (208483864).

221788136 is a wasteful number, since it uses less digits than its factorization.

221788136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2129 (or 2125 counting only the distinct ones).

The product of its digits is 32256, while the sum is 38.

The square root of 221788136 is about 14892.5530383477. The cubic root of 221788136 is about 605.3122136904.

The spelling of 221788136 in words is "two hundred twenty-one million, seven hundred eighty-eight thousand, one hundred thirty-six".