12978320 has 20 divisors (see below), whose sum is σ = 30174780. Its totient is φ = 5191296.

The previous prime is 12978313. The next prime is 12978323. The reversal of 12978320 is 2387921.

It can be written as a sum of positive squares in 2 ways, for example, as 9709456 + 3268864 = 3116^2 + 1808^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (12978323) 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 3 ways as a sum of consecutive naturals, for example, 81035 + ... + 81194.

It is an arithmetic number, because the mean of its divisors is an integer number (1508739).

Almost surely, 2^12978320 is an apocalyptic number.

12978320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12978320 is an abundant number, since it is smaller than the sum of its proper divisors (17196460).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12978320 is a wasteful number, since it uses less digits than its factorization.

12978320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162242 (or 162236 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 12978320 is about 3602.5435458853. The cubic root of 12978320 is about 235.0026859509.

The spelling of 12978320 in words is "twelve million, nine hundred seventy-eight thousand, three hundred twenty".