138281 has 8 divisors (see below), whose sum is σ = 162624. Its totient is φ = 115920.

The previous prime is 138251. The next prime is 138283. The reversal of 138281 is 182831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138281 is a prime.

It is a super-2 number, since 2×138281² = 38243269922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (138283) 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 in 7 ways as a sum of consecutive naturals, for example, 341 + ... + 626.

It is an arithmetic number, because the mean of its divisors is an integer number (20328).

2¹³⁸²⁸¹ is an apocalyptic number.

138281 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

138281 is a deficient number, since it is larger than the sum of its proper divisors (24343).

138281 is a wasteful number, since it uses less digits than its factorization.

138281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991.

The product of its digits is 384, while the sum is 23.

The square root of 138281 is about 371.8615333696. The cubic root of 138281 is about 51.7115438508.

The spelling of 138281 in words is "one hundred thirty-eight thousand, two hundred eighty-one".