42117815 has 4 divisors (see below), whose sum is σ = 50541384. Its totient is φ = 33694248.

The previous prime is 42117793. The next prime is 42117821. The reversal of 42117815 is 51871124.

42117815 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 42117815 - 2¹² = 42113719 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 4211777 + ... + 4211786.

It is an arithmetic number, because the mean of its divisors is an integer number (12635346).

Almost surely, 2^42117815 is an apocalyptic number.

42117815 is a deficient number, since it is larger than the sum of its proper divisors (8423569).

42117815 is an equidigital number, since it uses as much as digits as its factorization.

42117815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8423568.

The product of its digits is 2240, while the sum is 29.

The square root of 42117815 is about 6489.8239575508. The cubic root of 42117815 is about 347.9273833377.

Adding to 42117815 its reverse (51871124), we get a palindrome (93988939).

The spelling of 42117815 in words is "forty-two million, one hundred seventeen thousand, eight hundred fifteen".