221532768 has 72 divisors (see below), whose sum is σ = 632923200. Its totient is φ = 73499904.

The previous prime is 221532767. The next prime is 221532791. The reversal of 221532768 is 867235122.

It is a tau number, because it is divible by the number of its divisors (72).

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 (221532767) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 64273 + ... + 67631.

It is an arithmetic number, because the mean of its divisors is an integer number (8790600).

Almost surely, 2^221532768 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 221532768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (316461600).

221532768 is an abundant number, since it is smaller than the sum of its proper divisors (411390432).

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

221532768 is a wasteful number, since it uses less digits than its factorization.

221532768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3604 (or 3593 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 221532768 is about 14883.9768879154. The cubic root of 221532768 is about 605.0798046037.

The spelling of 221532768 in words is "two hundred twenty-one million, five hundred thirty-two thousand, seven hundred sixty-eight".