111216321 has 10 divisors (see below), whose sum is σ = 166138082. Its totient is φ = 74144160.

The previous prime is 111216319. The next prime is 111216323. The reversal of 111216321 is 123612111.

111216321 is a `hidden beast` number, since 1 + 11 + 21 + 632 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (111216319) and next prime (111216323).

It can be written as a sum of positive squares in only one way, i.e., 105267600 + 5948721 = 10260^2 + 2439^2 .

It is not a de Polignac number, because 111216321 - 2¹ = 111216319 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 111216294 and 111216303.

It is not an unprimeable number, because it can be changed into a prime (111216323) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 686440 + ... + 686601.

Almost surely, 2^111216321 is an apocalyptic number.

It is an amenable number.

111216321 is a deficient number, since it is larger than the sum of its proper divisors (54921761).

111216321 is an equidigital number, since it uses as much as digits as its factorization.

111216321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1373053 (or 1373044 counting only the distinct ones).

The product of its digits is 72, while the sum is 18.

The square root of 111216321 is about 10545.9148962999. The cubic root of 111216321 is about 480.9015478181.

Adding to 111216321 its reverse (123612111), we get a palindrome (234828432).

The spelling of 111216321 in words is "one hundred eleven million, two hundred sixteen thousand, three hundred twenty-one".