111212221 has 8 divisors (see below), whose sum is σ = 114960384. Its totient is φ = 107474160.

The previous prime is 111212203. The next prime is 111212239. The reversal of 111212221 is 122212111.

It is an interprime number because it is at equal distance from previous prime (111212203) and next prime (111212239).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 111212221 - 2¹³ = 111204029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111212201) 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, 24675 + ... + 28831.

It is an arithmetic number, because the mean of its divisors is an integer number (14370048).

Almost surely, 2^111212221 is an apocalyptic number.

It is an amenable number.

111212221 is a deficient number, since it is larger than the sum of its proper divisors (3748163).

111212221 is an equidigital number, since it uses as much as digits as its factorization.

111212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5051.

The product of its digits is 16, while the sum is 13.

The square root of 111212221 is about 10545.7205064424. The cubic root of 111212221 is about 480.8956382520.

Adding to 111212221 its reverse (122212111), we get a palindrome (233424332).

The spelling of 111212221 in words is "one hundred eleven million, two hundred twelve thousand, two hundred twenty-one".