42815 has 4 divisors (see below), whose sum is σ = 51384. Its totient is φ = 34248.

The previous prime is 42797. The next prime is 42821. The reversal of 42815 is 51824.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 42815 - 2⁶ = 42751 is a prime.

It is a Duffinian number.

It is a plaindrome in base 8.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 42815.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 4277 + ... + 4286.

It is an arithmetic number, because the mean of its divisors is an integer number (12846).

2⁴²⁸¹⁵ is an apocalyptic number.

42815 is a deficient number, since it is larger than the sum of its proper divisors (8569).

42815 is an equidigital number, since it uses as much as digits as its factorization.

42815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8568.

The product of its digits is 320, while the sum is 20.

The square root of 42815 is about 206.9178580983. The cubic root of 42815 is about 34.9836658476.

Subtracting 42815 from its reverse (51824), we obtain a palindrome (9009).

The spelling of 42815 in words is "forty-two thousand, eight hundred fifteen".