42840065 has 8 divisors (see below), whose sum is σ = 51490728. Its totient is φ = 34216960.

The previous prime is 42839999. The next prime is 42840067. The reversal of 42840065 is 56004824.

It can be written as a sum of positive squares in 4 ways, for example, as 16129 + 42823936 = 127^2 + 6544^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-42840065 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (42840067) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3296 + ... + 9825.

It is an arithmetic number, because the mean of its divisors is an integer number (6436341).

Almost surely, 2^42840065 is an apocalyptic number.

It is an amenable number.

42840065 is a deficient number, since it is larger than the sum of its proper divisors (8650663).

42840065 is a wasteful number, since it uses less digits than its factorization.

42840065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13779.

The product of its (nonzero) digits is 7680, while the sum is 29.

The square root of 42840065 is about 6545.2322342297. The cubic root of 42840065 is about 349.9049129449.

Adding to 42840065 its reverse (56004824), we get a palindrome (98844889).

The spelling of 42840065 in words is "forty-two million, eight hundred forty thousand, sixty-five".