221145288 has 96 divisors (see below), whose sum is σ = 684273600. Its totient is φ = 58316544.

The previous prime is 221145269. The next prime is 221145311. The reversal of 221145288 is 882541122.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24498 + ... + 32286.

It is an arithmetic number, because the mean of its divisors is an integer number (7127850).

Almost surely, 2^221145288 is an apocalyptic number.

221145288 is a gapful number since it is divisible by the number (28) 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 221145288, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (342136800).

221145288 is an abundant number, since it is smaller than the sum of its proper divisors (463128312).

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

221145288 is a wasteful number, since it uses less digits than its factorization.

221145288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7831 (or 7814 counting only the distinct ones).

The product of its digits is 10240, while the sum is 33.

The square root of 221145288 is about 14870.9545087059. The cubic root of 221145288 is about 604.7268197268.

The spelling of 221145288 in words is "two hundred twenty-one million, one hundred forty-five thousand, two hundred eighty-eight".