8139281 has 4 divisors (see below), whose sum is σ = 8250852. Its totient is φ = 8027712.

The previous prime is 8139253. The next prime is 8139283. The reversal of 8139281 is 1829318.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6330256 + 1809025 = 2516^2 + 1345^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8139281 is a prime.

It is a super-2 number, since 2×8139281² = 132495790393922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8139283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55676 + ... + 55821.

It is an arithmetic number, because the mean of its divisors is an integer number (2062713).

Almost surely, 2^8139281 is an apocalyptic number.

It is an amenable number.

8139281 is a deficient number, since it is larger than the sum of its proper divisors (111571).

8139281 is a wasteful number, since it uses less digits than its factorization.

8139281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111570.

The product of its digits is 3456, while the sum is 32.

The square root of 8139281 is about 2852.9425160700. The cubic root of 8139281 is about 201.1540035720.

The spelling of 8139281 in words is "eight million, one hundred thirty-nine thousand, two hundred eighty-one".