42840557 has 2 divisors, whose sum is σ = 42840558. Its totient is φ = 42840556.

The previous prime is 42840517. The next prime is 42840563. The reversal of 42840557 is 75504824.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30316036 + 12524521 = 5506^2 + 3539^2 .

It is a cyclic number.

It is not a de Polignac number, because 42840557 - 2¹⁶ = 42775021 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42840517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21420278 + 21420279.

It is an arithmetic number, because the mean of its divisors is an integer number (21420279).

Almost surely, 2^42840557 is an apocalyptic number.

It is an amenable number.

42840557 is a deficient number, since it is larger than the sum of its proper divisors (1).

42840557 is an equidigital number, since it uses as much as digits as its factorization.

42840557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 44800, while the sum is 35.

The square root of 42840557 is about 6545.2698187317. The cubic root of 42840557 is about 349.9062524430.

The spelling of 42840557 in words is "forty-two million, eight hundred forty thousand, five hundred fifty-seven".