139281 has 8 divisors (see below), whose sum is σ = 196704. Its totient is φ = 87360.

The previous prime is 139273. The next prime is 139291. The reversal of 139281 is 182931.

139281 is nontrivially palindromic in base 2.

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

It is not a de Polignac number, because 139281 - 2³ = 139273 is a prime.

It is a super-2 number, since 2×139281² = 38798393922, which contains 22 as substring.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

139281 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 139281.

It is not an unprimeable number, because it can be changed into a prime (139201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1315 + ... + 1416.

It is an arithmetic number, because the mean of its divisors is an integer number (24588).

139281 is a Friedman number, since it can be written as (9+8)*(2^13+1), using all its digits and the basic arithmetic operations.

2¹³⁹²⁸¹ is an apocalyptic number.

It is an amenable number.

139281 is a deficient number, since it is larger than the sum of its proper divisors (57423).

139281 is a wasteful number, since it uses less digits than its factorization.

139281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2751.

The product of its digits is 432, while the sum is 24.

The square root of 139281 is about 373.2036977309. The cubic root of 139281 is about 51.8358978569.

The spelling of 139281 in words is "one hundred thirty-nine thousand, two hundred eighty-one".