221532160 has 104 divisors (see below), whose sum is σ = 551418120. Its totient is φ = 85327872.

The previous prime is 221532139. The next prime is 221532161. The reversal of 221532160 is 61235122.

It can be written as a sum of positive squares in 4 ways, for example, as 26873856 + 194658304 = 5184^2 + 13952^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221532161) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 593734 + ... + 594106.

Almost surely, 2^221532160 is an apocalyptic number.

221532160 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 221532160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275709060).

221532160 is an abundant number, since it is smaller than the sum of its proper divisors (329885960).

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

221532160 is an equidigital number, since it uses as much as digits as its factorization.

221532160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431 (or 409 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 221532160 is about 14883.9564632526. The cubic root of 221532160 is about 605.0792510530.

Adding to 221532160 its reverse (61235122), we get a palindrome (282767282).

The spelling of 221532160 in words is "two hundred twenty-one million, five hundred thirty-two thousand, one hundred sixty".