221323020 has 144 divisors (see below), whose sum is σ = 683773440. Its totient is φ = 53336448.

The previous prime is 221323019. The next prime is 221323049. The reversal of 221323020 is 20323122.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 602877 + ... + 603243.

Almost surely, 2^221323020 is an apocalyptic number.

221323020 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 221323020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (341886720).

221323020 is an abundant number, since it is smaller than the sum of its proper divisors (462450420).

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

221323020 is a wasteful number, since it uses less digits than its factorization.

221323020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 444 (or 419 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 221323020 is about 14876.9291186051. The cubic root of 221323020 is about 604.8887804114. Note that the first 3 decimals are identical.

Adding to 221323020 its reverse (20323122), we get a palindrome (241646142).

It can be divided in two parts, 22132 and 3020, that added together give a palindrome (25152).

The spelling of 221323020 in words is "two hundred twenty-one million, three hundred twenty-three thousand, twenty".