221663124 has 72 divisors (see below), whose sum is σ = 582702120. Its totient is φ = 70963200.

The previous prime is 221663093. The next prime is 221663129. The reversal of 221663124 is 421366122.

221663124 is a `hidden beast` number, since 2 + 2 + 1 + 6 + 631 + 24 = 666.

221663124 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 27562500 + 194100624 = 5250^2 + 13932^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221663129) 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, 251164 + ... + 252044.

It is an arithmetic number, because the mean of its divisors is an integer number (8093085).

Almost surely, 2^221663124 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 221663124, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (291351060).

221663124 is an abundant number, since it is smaller than the sum of its proper divisors (361038996).

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

221663124 is a wasteful number, since it uses less digits than its factorization.

221663124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1161 (or 1156 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 221663124 is about 14888.3553154806. The cubic root of 221663124 is about 605.1984632230.

The spelling of 221663124 in words is "two hundred twenty-one million, six hundred sixty-three thousand, one hundred twenty-four".