221253440 has 84 divisors (see below), whose sum is σ = 540027876. Its totient is φ = 86341632.

The previous prime is 221253433. The next prime is 221253449. The reversal of 221253440 is 44352122.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 27709696 + 193543744 = 5264^2 + 13912^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221253449) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 706724 + ... + 707036.

Almost surely, 2^221253440 is an apocalyptic number.

221253440 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 221253440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (270013938).

221253440 is an abundant number, since it is smaller than the sum of its proper divisors (318774436).

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

221253440 is an equidigital number, since it uses as much as digits as its factorization.

221253440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424 (or 367 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 23.

The square root of 221253440 is about 14874.5904145291. The cubic root of 221253440 is about 604.8253850286.

The spelling of 221253440 in words is "two hundred twenty-one million, two hundred fifty-three thousand, four hundred forty".