111217609 has 2 divisors, whose sum is σ = 111217610. Its totient is φ = 111217608.

The previous prime is 111217607. The next prime is 111217637. The reversal of 111217609 is 906712111.

It is an a-pointer prime, because the next prime (111217637) can be obtained adding 111217609 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84125584 + 27092025 = 9172^2 + 5205^2 .

It is an emirp because it is prime and its reverse (906712111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 111217609 - 2¹ = 111217607 is a prime.

Together with 111217607, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (111217607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55608804 + 55608805.

It is an arithmetic number, because the mean of its divisors is an integer number (55608805).

Almost surely, 2^111217609 is an apocalyptic number.

It is an amenable number.

111217609 is a deficient number, since it is larger than the sum of its proper divisors (1).

111217609 is an equidigital number, since it uses as much as digits as its factorization.

111217609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 28.

The square root of 111217609 is about 10545.9759624228. The cubic root of 111217609 is about 480.9034042566.

It can be divided in two parts, 1112 and 17609, that added together give a triangular number (18721 = T₁₉₃).

The spelling of 111217609 in words is "one hundred eleven million, two hundred seventeen thousand, six hundred nine".