12978945 has 24 divisors (see below), whose sum is σ = 25711296. Its totient is φ = 5933088.

The previous prime is 12978937. The next prime is 12978947. The reversal of 12978945 is 54987921.

It is not a de Polignac number, because 12978945 - 2³ = 12978937 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12978945.

It is not an unprimeable number, because it can be changed into a prime (12978947) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20287 + ... + 20916.

It is an arithmetic number, because the mean of its divisors is an integer number (1071304).

Almost surely, 2^12978945 is an apocalyptic number.

12978945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

12978945 is a deficient number, since it is larger than the sum of its proper divisors (12732351).

12978945 is a wasteful number, since it uses less digits than its factorization.

12978945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41221 (or 41218 counting only the distinct ones).

The product of its digits is 181440, while the sum is 45.

The square root of 12978945 is about 3602.6302891082. The cubic root of 12978945 is about 235.0064582502.

The spelling of 12978945 in words is "twelve million, nine hundred seventy-eight thousand, nine hundred forty-five".