221794560 has 216 divisors, whose sum is σ = 826973784. Its totient is φ = 54558720.

The previous prime is 221794541. The next prime is 221794561. The reversal of 221794560 is 65497122.

221794560 is a `hidden beast` number, since 2 + 2 + 1 + 7 + 94 + 560 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1806336 + 219988224 = 1344^2 + 14832^2 .

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221794561) 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, 149020 + ... + 150500.

Almost surely, 2^221794560 is an apocalyptic number.

221794560 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 221794560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (413486892).

221794560 is an abundant number, since it is smaller than the sum of its proper divisors (605179224).

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

221794560 is a wasteful number, since it uses less digits than its factorization.

221794560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1521 (or 1504 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 221794560 is about 14892.7687150509. The cubic root of 221794560 is about 605.3180578385.

The spelling of 221794560 in words is "two hundred twenty-one million, seven hundred ninety-four thousand, five hundred sixty".