221423124 has 72 divisors (see below), whose sum is σ = 573314112. Its totient is φ = 66443520.

The previous prime is 221423123. The next prime is 221423171. The reversal of 221423124 is 421324122.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 221423124.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221423123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81817 + ... + 84479.

It is an arithmetic number, because the mean of its divisors is an integer number (7962696).

Almost surely, 2^221423124 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 221423124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286657056).

221423124 is an abundant number, since it is smaller than the sum of its proper divisors (351890988).

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

221423124 is a wasteful number, since it uses less digits than its factorization.

221423124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2737 (or 2722 counting only the distinct ones).

The product of its digits is 768, while the sum is 21.

The square root of 221423124 is about 14880.2931422738. The cubic root of 221423124 is about 604.9799633644.

Adding to 221423124 its reverse (421324122), we get a palindrome (642747246).

The spelling of 221423124 in words is "two hundred twenty-one million, four hundred twenty-three thousand, one hundred twenty-four".