221423220 has 120 divisors (see below), whose sum is σ = 701885184. Its totient is φ = 58428864.

The previous prime is 221423203. The next prime is 221423243. The reversal of 221423220 is 22324122.

221423220 is a `hidden beast` number, since 2 + 21 + 423 + 220 = 666.

221423220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 221423193 and 221423202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 166197 + ... + 167523.

Almost surely, 2^221423220 is an apocalyptic number.

221423220 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 221423220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (350942592).

221423220 is an abundant number, since it is smaller than the sum of its proper divisors (480461964).

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

221423220 is a wasteful number, since it uses less digits than its factorization.

221423220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1451 (or 1440 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 221423220 is about 14880.2963680163. The cubic root of 221423220 is about 604.9800507959.

Adding to 221423220 its reverse (22324122), we get a palindrome (243747342).

The spelling of 221423220 in words is "two hundred twenty-one million, four hundred twenty-three thousand, two hundred twenty".