111500561 has 2 divisors, whose sum is σ = 111500562. Its totient is φ = 111500560.

The previous prime is 111500551. The next prime is 111500567. The reversal of 111500561 is 165005111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84916225 + 26584336 = 9215^2 + 5156^2 .

It is a cyclic number.

It is not a de Polignac number, because 111500561 - 2²² = 107306257 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (111500567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55750280 + 55750281.

It is an arithmetic number, because the mean of its divisors is an integer number (55750281).

Almost surely, 2^111500561 is an apocalyptic number.

It is an amenable number.

111500561 is a deficient number, since it is larger than the sum of its proper divisors (1).

111500561 is an equidigital number, since it uses as much as digits as its factorization.

111500561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 150, while the sum is 20.

The square root of 111500561 is about 10559.3826050579. The cubic root of 111500561 is about 481.3108857357.

Adding to 111500561 its reverse (165005111), we get a palindrome (276505672).

The spelling of 111500561 in words is "one hundred eleven million, five hundred thousand, five hundred sixty-one".