221540352 has 156 divisors (see below), whose sum is σ = 653641800. Its totient is φ = 66682880.

The previous prime is 221540321. The next prime is 221540357. The reversal of 221540352 is 253045122.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221540357) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1486774 + ... + 1486922.

Almost surely, 2^221540352 is an apocalyptic number.

221540352 is a gapful number since it is divisible by the number (22) 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 221540352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326820900).

221540352 is an abundant number, since it is smaller than the sum of its proper divisors (432101448).

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

221540352 is a wasteful number, since it uses less digits than its factorization.

221540352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 221540352 is about 14884.2316563536. The cubic root of 221540352 is about 605.0867093352.

Adding to 221540352 its reverse (253045122), we get a palindrome (474585474).

The spelling of 221540352 in words is "two hundred twenty-one million, five hundred forty thousand, three hundred fifty-two".