221642124 has 96 divisors (see below), whose sum is σ = 611525376. Its totient is φ = 61716480.

The previous prime is 221642123. The next prime is 221642137. The reversal of 221642124 is 421246122.

It is a happy number.

It is a super-2 number, since 2×221642124² = 98250462262462752, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 221642094 and 221642103.

It is not an unprimeable number, because it can be changed into a prime (221642123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 95344 + ... + 97640.

It is an arithmetic number, because the mean of its divisors is an integer number (6370056).

Almost surely, 2^221642124 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 221642124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (305762688).

221642124 is an abundant number, since it is smaller than the sum of its proper divisors (389883252).

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

221642124 is a wasteful number, since it uses less digits than its factorization.

221642124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2375 (or 2373 counting only the distinct ones).

The product of its digits is 1536, while the sum is 24.

The square root of 221642124 is about 14887.6500496217. The cubic root of 221642124 is about 605.1793507836.

Adding to 221642124 its reverse (421246122), we get a palindrome (642888246).

The spelling of 221642124 in words is "two hundred twenty-one million, six hundred forty-two thousand, one hundred twenty-four".