221106440 has 64 divisors (see below), whose sum is σ = 527310000. Its totient is φ = 83292160.

The previous prime is 221106421. The next prime is 221106443. The reversal of 221106440 is 44601122.

It can be written as a sum of positive squares in 8 ways, for example, as 105801796 + 115304644 = 10286^2 + 10738^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (221106443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45236 + ... + 49884.

Almost surely, 2^221106440 is an apocalyptic number.

221106440 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 221106440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263655000).

221106440 is an abundant number, since it is smaller than the sum of its proper divisors (306203560).

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

221106440 is a wasteful number, since it uses less digits than its factorization.

221106440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4730 (or 4726 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 221106440 is about 14869.6482809783. The cubic root of 221106440 is about 604.6914074066.

Adding to 221106440 its reverse (44601122), we get a palindrome (265707562).

The spelling of 221106440 in words is "two hundred twenty-one million, one hundred six thousand, four hundred forty".