221032440 has 96 divisors (see below), whose sum is σ = 725587200. Its totient is φ = 58348800.

The previous prime is 221032439. The next prime is 221032447. The reversal of 221032440 is 44230122.

221032440 is a `hidden beast` number, since 221 + 0 + 3 + 2 + 440 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221032447) 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 23 ways as a sum of consecutive naturals, for example, 33321 + ... + 39399.

It is an arithmetic number, because the mean of its divisors is an integer number (7558200).

Almost surely, 2^221032440 is an apocalyptic number.

221032440 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 221032440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (362793600).

221032440 is an abundant number, since it is smaller than the sum of its proper divisors (504554760).

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

221032440 is a wasteful number, since it uses less digits than its factorization.

221032440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6197 (or 6190 counting only the distinct ones).

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

The square root of 221032440 is about 14867.1597825543. The cubic root of 221032440 is about 604.6239404179.

Adding to 221032440 its reverse (44230122), we get a palindrome (265262562).

The spelling of 221032440 in words is "two hundred twenty-one million, thirty-two thousand, four hundred forty".