221722732 has 48 divisors (see below), whose sum is σ = 486420480. Its totient is φ = 85910400.

The previous prime is 221722729. The next prime is 221722741. The reversal of 221722732 is 237227122.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a self number, because there is not a number n which added to its sum of digits gives 221722732.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56944 + ... + 60712.

It is an arithmetic number, because the mean of its divisors is an integer number (10133760).

Almost surely, 2^221722732 is an apocalyptic number.

221722732 is a gapful number since it is divisible by the number (22) 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 221722732, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (243210240).

221722732 is an abundant number, since it is smaller than the sum of its proper divisors (264697748).

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

221722732 is a wasteful number, since it uses less digits than its factorization.

221722732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3982 (or 3980 counting only the distinct ones).

The product of its digits is 4704, while the sum is 28.

The square root of 221722732 is about 14890.3570138530. The cubic root of 221722732 is about 605.2527068521.

Adding to 221722732 its reverse (237227122), we get a palindrome (458949854).

The spelling of 221722732 in words is "two hundred twenty-one million, seven hundred twenty-two thousand, seven hundred thirty-two".