221725440 has 216 divisors, whose sum is σ = 808320240. Its totient is φ = 55959552.

The previous prime is 221725397. The next prime is 221725457. The reversal of 221725440 is 44527122.

221725440 is a `hidden beast` number, since 2 + 217 + 2 + 5 + 440 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 218374 + ... + 219386.

Almost surely, 2^221725440 is an apocalyptic number.

221725440 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 221725440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (404160120).

221725440 is an abundant number, since it is smaller than the sum of its proper divisors (586594800).

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

221725440 is a wasteful number, since it uses less digits than its factorization.

221725440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1059 (or 1042 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 27.

The square root of 221725440 is about 14890.4479449075. The cubic root of 221725440 is about 605.2551709171.

The spelling of 221725440 in words is "two hundred twenty-one million, seven hundred twenty-five thousand, four hundred forty".