221405324 has 18 divisors (see below), whose sum is σ = 450718380. Its totient is φ = 94887912.

The previous prime is 221405281. The next prime is 221405339. The reversal of 221405324 is 423504122.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 221405324.

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, 564614 + ... + 565005.

It is an arithmetic number, because the mean of its divisors is an integer number (25039910).

Almost surely, 2^221405324 is an apocalyptic number.

It is an amenable number.

221405324 is an abundant number, since it is smaller than the sum of its proper divisors (229313056).

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

221405324 is a wasteful number, since it uses less digits than its factorization.

221405324 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1129637 (or 1129628 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 221405324 is about 14879.6950237564. The cubic root of 221405324 is about 604.9637516702.

Adding to 221405324 its reverse (423504122), we get a palindrome (644909446).

The spelling of 221405324 in words is "two hundred twenty-one million, four hundred five thousand, three hundred twenty-four".