138742 has 4 divisors (see below), whose sum is σ = 208116. Its totient is φ = 69370.

The previous prime is 138739. The next prime is 138763. The reversal of 138742 is 247831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 247831 = 47 ⋅5273.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34684 + ... + 34687.

It is an arithmetic number, because the mean of its divisors is an integer number (52029).

2¹³⁸⁷⁴² is an apocalyptic number.

138742 is a deficient number, since it is larger than the sum of its proper divisors (69374).

138742 is an equidigital number, since it uses as much as digits as its factorization.

138742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69373.

The product of its digits is 1344, while the sum is 25.

The square root of 138742 is about 372.4808719921. The cubic root of 138742 is about 51.7689452755.

The spelling of 138742 in words is "one hundred thirty-eight thousand, seven hundred forty-two".