221306124 has 48 divisors (see below), whose sum is σ = 559893600. Its totient is φ = 67630080.

The previous prime is 221306089. The next prime is 221306131. The reversal of 221306124 is 421603122.

It is a self number, because there is not a number n which added to its sum of digits gives 221306124.

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 15 ways as a sum of consecutive naturals, for example, 18484 + ... + 28004.

It is an arithmetic number, because the mean of its divisors is an integer number (11664450).

Almost surely, 2^221306124 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221306124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (279946800).

221306124 is an abundant number, since it is smaller than the sum of its proper divisors (338587476).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221306124 is a wasteful number, since it uses less digits than its factorization.

221306124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9690 (or 9688 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 221306124 is about 14876.3612486387. The cubic root of 221306124 is about 604.8733874337.

Adding to 221306124 its reverse (421603122), we get a palindrome (642909246).

The spelling of 221306124 in words is "two hundred twenty-one million, three hundred six thousand, one hundred twenty-four".