42538 has 4 divisors (see below), whose sum is σ = 63810. Its totient is φ = 21268.

The previous prime is 42533. The next prime is 42557. The reversal of 42538 is 83524.

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

It can be written as a sum of positive squares in only one way, i.e., 34969 + 7569 = 187^2 + 87^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (42533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10633 + ... + 10636.

2⁴²⁵³⁸ is an apocalyptic number.

42538 is a deficient number, since it is larger than the sum of its proper divisors (21272).

42538 is a wasteful number, since it uses less digits than its factorization.

42538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21271.

The product of its digits is 960, while the sum is 22.

The square root of 42538 is about 206.2474242263. The cubic root of 42538 is about 34.9080580075.

The spelling of 42538 in words is "forty-two thousand, five hundred thirty-eight".