42078161 has 2 divisors, whose sum is σ = 42078162. Its totient is φ = 42078160.

The previous prime is 42078143. The next prime is 42078167. The reversal of 42078161 is 16187024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 32035600 + 10042561 = 5660^2 + 3169^2 .

It is a cyclic number.

It is not a de Polignac number, because 42078161 - 2⁶ = 42078097 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (42078167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21039080 + 21039081.

It is an arithmetic number, because the mean of its divisors is an integer number (21039081).

Almost surely, 2^42078161 is an apocalyptic number.

It is an amenable number.

42078161 is a deficient number, since it is larger than the sum of its proper divisors (1).

42078161 is an equidigital number, since it uses as much as digits as its factorization.

42078161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 42078161 is about 6486.7681475447. The cubic root of 42078161 is about 347.8181576288.

The spelling of 42078161 in words is "forty-two million, seventy-eight thousand, one hundred sixty-one".