111212109 has 24 divisors (see below), whose sum is σ = 169434720. Its totient is φ = 72875376.

The previous prime is 111212099. The next prime is 111212117. The reversal of 111212109 is 901212111.

It is a happy number.

It is not a de Polignac number, because 111212109 - 2⁸ = 111211853 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111212091 and 111212100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111212119) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10459 + ... + 18215.

It is an arithmetic number, because the mean of its divisors is an integer number (7059780).

Almost surely, 2^111212109 is an apocalyptic number.

It is an amenable number.

111212109 is a deficient number, since it is larger than the sum of its proper divisors (58222611).

111212109 is an frugal number, since it uses more digits than its factorization.

111212109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7831 (or 7819 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 18.

The square root of 111212109 is about 10545.7151962302. The cubic root of 111212109 is about 480.8954768179.

The spelling of 111212109 in words is "one hundred eleven million, two hundred twelve thousand, one hundred nine".