12978247 has 4 divisors (see below), whose sum is σ = 13124160. Its totient is φ = 12832336.

The previous prime is 12978239. The next prime is 12978307. The reversal of 12978247 is 74287921.

12978247 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 12978247 - 2³ = 12978239 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12978227) 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, 72823 + ... + 73000.

It is an arithmetic number, because the mean of its divisors is an integer number (3281040).

Almost surely, 2^12978247 is an apocalyptic number.

12978247 is a deficient number, since it is larger than the sum of its proper divisors (145913).

12978247 is an equidigital number, since it uses as much as digits as its factorization.

12978247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145912.

The product of its digits is 56448, while the sum is 40.

The square root of 12978247 is about 3602.5334141407. The cubic root of 12978247 is about 235.0022453384.

It can be divided in two parts, 12978 and 247, that added together give a square (13225 = 115²).

The spelling of 12978247 in words is "twelve million, nine hundred seventy-eight thousand, two hundred forty-seven".