221266560 has 128 divisors (see below), whose sum is σ = 746884800. Its totient is φ = 55525376.

The previous prime is 221266541. The next prime is 221266613. The reversal of 221266560 is 65662122.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29251 + ... + 36029.

Almost surely, 2^221266560 is an apocalyptic number.

221266560 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 221266560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (373442400).

221266560 is an abundant number, since it is smaller than the sum of its proper divisors (525618240).

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

221266560 is a wasteful number, since it uses less digits than its factorization.

221266560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6818 (or 6806 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 221266560 is about 14875.0314285382. The cubic root of 221266560 is about 604.8373398743.

The spelling of 221266560 in words is "two hundred twenty-one million, two hundred sixty-six thousand, five hundred sixty".