42505 has 4 divisors (see below), whose sum is σ = 51012. Its totient is φ = 34000.

The previous prime is 42499. The next prime is 42509. The reversal of 42505 is 50524.

It is a happy number.

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 8649 + 33856 = 93^2 + 184^2 .

It is not a de Polignac number, because 42505 - 2⁵ = 42473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42509) 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, 4246 + ... + 4255.

It is an arithmetic number, because the mean of its divisors is an integer number (12753).

2⁴²⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

42505 is a deficient number, since it is larger than the sum of its proper divisors (8507).

42505 is an equidigital number, since it uses as much as digits as its factorization.

42505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8506.

The product of its (nonzero) digits is 200, while the sum is 16.

The square root of 42505 is about 206.1674077055. The cubic root of 42505 is about 34.8990287166.

The spelling of 42505 in words is "forty-two thousand, five hundred five".