111368561 has 2 divisors, whose sum is σ = 111368562. Its totient is φ = 111368560.

The previous prime is 111368431. The next prime is 111368563. The reversal of 111368561 is 165863111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74995600 + 36372961 = 8660^2 + 6031^2 .

It is a cyclic number.

It is not a de Polignac number, because 111368561 - 2²⁶ = 44259697 is a prime.

Together with 111368563, 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 (111368563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55684280 + 55684281.

It is an arithmetic number, because the mean of its divisors is an integer number (55684281).

Almost surely, 2^111368561 is an apocalyptic number.

It is an amenable number.

111368561 is a deficient number, since it is larger than the sum of its proper divisors (1).

111368561 is an equidigital number, since it uses as much as digits as its factorization.

111368561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 32.

The square root of 111368561 is about 10553.1303886572. The cubic root of 111368561 is about 481.1208773505.

The spelling of 111368561 in words is "one hundred eleven million, three hundred sixty-eight thousand, five hundred sixty-one".