111123581 has 2 divisors, whose sum is σ = 111123582. Its totient is φ = 111123580.

The previous prime is 111123559. The next prime is 111123641. The reversal of 111123581 is 185321111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90421081 + 20702500 = 9509^2 + 4550^2 .

It is a cyclic number.

It is not a de Polignac number, because 111123581 - 2¹⁴ = 111107197 is a prime.

It is a super-2 number, since 2×111123581² = 24696900508527122, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111123541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55561790 + 55561791.

It is an arithmetic number, because the mean of its divisors is an integer number (55561791).

Almost surely, 2^111123581 is an apocalyptic number.

It is an amenable number.

111123581 is a deficient number, since it is larger than the sum of its proper divisors (1).

111123581 is an equidigital number, since it uses as much as digits as its factorization.

111123581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 240, while the sum is 23.

The square root of 111123581 is about 10541.5170160656. The cubic root of 111123581 is about 480.7678407883.

Adding to 111123581 its reverse (185321111), we get a palindrome (296444692).

The spelling of 111123581 in words is "one hundred eleven million, one hundred twenty-three thousand, five hundred eighty-one".