221424000 has 256 divisors, whose sum is σ = 840153600. Its totient is φ = 50534400.

The previous prime is 221423999. The next prime is 221424001. The reversal of 221424000 is 424122.

It is an interprime number because it is at equal distance from previous prime (221423999) and next prime (221424001).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221424001) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 335671 + ... + 336329.

It is an arithmetic number, because the mean of its divisors is an integer number (3281850).

Almost surely, 2^221424000 is an apocalyptic number.

221424000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221424000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (420076800).

221424000 is an abundant number, since it is smaller than the sum of its proper divisors (618729600).

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

221424000 is an equidigital number, since it uses as much as digits as its factorization.

221424000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 698 (or 676 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 221424000 is about 14880.3225771487. The cubic root of 221424000 is about 604.9807611759.

Adding to 221424000 its reverse (424122), we get a palindrome (221848122).

The spelling of 221424000 in words is "two hundred twenty-one million, four hundred twenty-four thousand".