221143440 has 160 divisors (see below), whose sum is σ = 789949440. Its totient is φ = 50130432.

The previous prime is 221143423. The next prime is 221143441. The reversal of 221143440 is 44341122.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is not an unprimeable number, because it can be changed into a prime (221143441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 233047 + ... + 233993.

It is an arithmetic number, because the mean of its divisors is an integer number (4937184).

Almost surely, 2^221143440 is an apocalyptic number.

221143440 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 221143440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (394974720).

221143440 is an abundant number, since it is smaller than the sum of its proper divisors (568806000).

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

221143440 is a wasteful number, since it uses less digits than its factorization.

221143440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1109 (or 1103 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 221143440 is about 14870.8923740306. The cubic root of 221143440 is about 604.7251352561.

Adding to 221143440 its reverse (44341122), we get a palindrome (265484562).

The spelling of 221143440 in words is "two hundred twenty-one million, one hundred forty-three thousand, four hundred forty".