42542165 has 4 divisors (see below), whose sum is σ = 51050604. Its totient is φ = 34033728.

The previous prime is 42542161. The next prime is 42542167. The reversal of 42542165 is 56124524.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5466244 + 37075921 = 2338^2 + 6089^2 .

It is a cyclic number.

It is not a de Polignac number, because 42542165 - 2² = 42542161 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42542161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4254212 + ... + 4254221.

It is an arithmetic number, because the mean of its divisors is an integer number (12762651).

Almost surely, 2^42542165 is an apocalyptic number.

It is an amenable number.

42542165 is a deficient number, since it is larger than the sum of its proper divisors (8508439).

42542165 is an equidigital number, since it uses as much as digits as its factorization.

42542165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8508438.

The product of its digits is 9600, while the sum is 29.

The square root of 42542165 is about 6522.4355113715. The cubic root of 42542165 is about 349.0919728154.

Adding to 42542165 its reverse (56124524), we get a palindrome (98666689).

The spelling of 42542165 in words is "forty-two million, five hundred forty-two thousand, one hundred sixty-five".