221131316 has 36 divisors (see below), whose sum is σ = 451896228. Its totient is φ = 94405248.

The previous prime is 221131307. The next prime is 221131321. The reversal of 221131316 is 613131122.

It can be written as a sum of positive squares in 2 ways, for example, as 30580900 + 190550416 = 5530^2 + 13804^2 .

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 11 ways as a sum of consecutive naturals, for example, 52256 + ... + 56328.

It is an arithmetic number, because the mean of its divisors is an integer number (12552673).

Almost surely, 2^221131316 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 221131316, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225948114).

221131316 is an abundant number, since it is smaller than the sum of its proper divisors (230764912).

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

221131316 is a wasteful number, since it uses less digits than its factorization.

221131316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4368 (or 4359 counting only the distinct ones).

The product of its digits is 216, while the sum is 20.

The square root of 221131316 is about 14870.4847264640. The cubic root of 221131316 is about 604.7140838747.

Adding to 221131316 its reverse (613131122), we get a palindrome (834262438).

The spelling of 221131316 in words is "two hundred twenty-one million, one hundred thirty-one thousand, three hundred sixteen".