42145865 has 16 divisors (see below), whose sum is σ = 51908688. Its totient is φ = 32837376.

The previous prime is 42145843. The next prime is 42145879. The reversal of 42145865 is 56854124.

It can be written as a sum of positive squares in 8 ways, for example, as 7441984 + 34703881 = 2728^2 + 5891^2 .

It is a cyclic number.

It is not a de Polignac number, because 42145865 - 2⁶ = 42145801 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41099 + ... + 42111.

It is an arithmetic number, because the mean of its divisors is an integer number (3244293).

Almost surely, 2^42145865 is an apocalyptic number.

It is an amenable number.

42145865 is a deficient number, since it is larger than the sum of its proper divisors (9762823).

42145865 is a wasteful number, since it uses less digits than its factorization.

42145865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1228.

The product of its digits is 38400, while the sum is 35.

The square root of 42145865 is about 6491.9846734261. The cubic root of 42145865 is about 348.0046047966.

Adding to 42145865 its reverse (56854124), we get a palindrome (98999989).

The spelling of 42145865 in words is "forty-two million, one hundred forty-five thousand, eight hundred sixty-five".