42139 has 2 divisors, whose sum is σ = 42140. Its totient is φ = 42138.

The previous prime is 42131. The next prime is 42157. The reversal of 42139 is 93124.

42139 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 42139 - 2³ = 42131 is a prime.

It is a plaindrome in base 7, base 8 and base 14.

It is a nialpdrome in base 15.

It is not a weakly prime, because it can be changed into another prime (42131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21069 + 21070.

It is an arithmetic number, because the mean of its divisors is an integer number (21070).

2⁴²¹³⁹ is an apocalyptic number.

42139 is a deficient number, since it is larger than the sum of its proper divisors (1).

42139 is an equidigital number, since it uses as much as digits as its factorization.

42139 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 19.

The square root of 42139 is about 205.2778604721. The cubic root of 42139 is about 34.7985708666.

It can be divided in two parts, 42 and 139, that added together give a palindrome (181).

The spelling of 42139 in words is "forty-two thousand, one hundred thirty-nine".