221436440 has 64 divisors (see below), whose sum is σ = 512244000. Its totient is φ = 86118400.

The previous prime is 221436421. The next prime is 221436451. The reversal of 221436440 is 44634122.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 237896 + ... + 238824.

Almost surely, 2^221436440 is an apocalyptic number.

221436440 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 221436440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (256122000).

221436440 is an abundant number, since it is smaller than the sum of its proper divisors (290807560).

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

221436440 is a wasteful number, since it uses less digits than its factorization.

221436440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1100 (or 1096 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 26.

The square root of 221436440 is about 14880.7405729688. The cubic root of 221436440 is about 604.9920906008.

The spelling of 221436440 in words is "two hundred twenty-one million, four hundred thirty-six thousand, four hundred forty".