221056640 has 256 divisors, whose sum is σ = 660960000. Its totient is φ = 70447104.

The previous prime is 221056637. The next prime is 221056673. The reversal of 221056640 is 46650122.

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 31 ways as a sum of consecutive naturals, for example, 4170854 + ... + 4170906.

It is an arithmetic number, because the mean of its divisors is an integer number (2581875).

Almost surely, 2^221056640 is an apocalyptic number.

221056640 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 221056640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330480000).

221056640 is an abundant number, since it is smaller than the sum of its proper divisors (439903360).

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

221056640 is an equidigital number, since it uses as much as digits as its factorization.

221056640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 221056640 is about 14867.9736346282. The cubic root of 221056640 is about 604.6460056035.

The spelling of 221056640 in words is "two hundred twenty-one million, fifty-six thousand, six hundred forty".