221057568 has 144 divisors (see below), whose sum is σ = 653974776. Its totient is φ = 70778880.

The previous prime is 221057561. The next prime is 221057611. The reversal of 221057568 is 865750122.

It is a happy number.

221057568 is a `hidden beast` number, since 2 + 21 + 0 + 575 + 68 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 99440784 + 121616784 = 9972^2 + 11028^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (221057561) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1145280 + ... + 1145472.

Almost surely, 2^221057568 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221057568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326987388).

221057568 is an abundant number, since it is smaller than the sum of its proper divisors (432917208).

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

221057568 is a wasteful number, since it uses less digits than its factorization.

221057568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 347 (or 336 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 221057568 is about 14868.0048426142. The cubic root of 221057568 is about 604.6468517074.

The spelling of 221057568 in words is "two hundred twenty-one million, fifty-seven thousand, five hundred sixty-eight".