111661601 has 2 divisors, whose sum is σ = 111661602. Its totient is φ = 111661600.

The previous prime is 111661577. The next prime is 111661609. The reversal of 111661601 is 106166111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84621601 + 27040000 = 9199^2 + 5200^2 .

It is an emirp because it is prime and its reverse (106166111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 111661601 - 2²⁶ = 44552737 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (111661609) 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, 55830800 + 55830801.

It is an arithmetic number, because the mean of its divisors is an integer number (55830801).

Almost surely, 2^111661601 is an apocalyptic number.

It is an amenable number.

111661601 is a deficient number, since it is larger than the sum of its proper divisors (1).

111661601 is an equidigital number, since it uses as much as digits as its factorization.

111661601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 23.

The square root of 111661601 is about 10567.0052995160. The cubic root of 111661601 is about 481.5424929978.

The spelling of 111661601 in words is "one hundred eleven million, six hundred sixty-one thousand, six hundred one".