42840517 has 2 divisors, whose sum is σ = 42840518. Its totient is φ = 42840516.

The previous prime is 42840491. The next prime is 42840557. The reversal of 42840517 is 71504824.

42840517 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 42432196 + 408321 = 6514^2 + 639^2 .

It is a cyclic number.

It is not a de Polignac number, because 42840517 - 2⁷ = 42840389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42840557) 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, 21420258 + 21420259.

It is an arithmetic number, because the mean of its divisors is an integer number (21420259).

Almost surely, 2^42840517 is an apocalyptic number.

It is an amenable number.

42840517 is a deficient number, since it is larger than the sum of its proper divisors (1).

42840517 is an equidigital number, since it uses as much as digits as its factorization.

42840517 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 42840517 is about 6545.2667630892. The cubic root of 42840517 is about 349.9061435411.

The spelling of 42840517 in words is "forty-two million, eight hundred forty thousand, five hundred seventeen".