221424500 has 96 divisors (see below), whose sum is σ = 533385216. Its totient is φ = 79632000.

The previous prime is 221424493. The next prime is 221424503. The reversal of 221424500 is 5424122.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221424503) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 698342 + ... + 698658.

It is an arithmetic number, because the mean of its divisors is an integer number (5556096).

Almost surely, 2^221424500 is an apocalyptic number.

221424500 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 221424500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (266692608).

221424500 is an abundant number, since it is smaller than the sum of its proper divisors (311960716).

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

221424500 is a wasteful number, since it uses less digits than its factorization.

221424500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474 (or 462 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 221424500 is about 14880.3393778502. The cubic root of 221424500 is about 604.9812165468.

Adding to 221424500 its reverse (5424122), we get a palindrome (226848622).

The spelling of 221424500 in words is "two hundred twenty-one million, four hundred twenty-four thousand, five hundred".