12840047 has 4 divisors (see below), whose sum is σ = 14007336. Its totient is φ = 11672760.

The previous prime is 12840031. The next prime is 12840089. The reversal of 12840047 is 74004821.

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

It is not a de Polignac number, because 12840047 - 2⁴ = 12840031 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12839998 and 12840025.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12840007) 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, 583628 + ... + 583649.

It is an arithmetic number, because the mean of its divisors is an integer number (3501834).

Almost surely, 2^12840047 is an apocalyptic number.

12840047 is a deficient number, since it is larger than the sum of its proper divisors (1167289).

12840047 is a wasteful number, since it uses less digits than its factorization.

12840047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1167288.

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 12840047 is about 3583.3011316383. The cubic root of 12840047 is about 234.1651195354.

Adding to 12840047 its reverse (74004821), we get a palindrome (86844868).

The spelling of 12840047 in words is "twelve million, eight hundred forty thousand, forty-seven".