12378640 has 20 divisors (see below), whose sum is σ = 28780524. Its totient is φ = 4951424.

The previous prime is 12378631. The next prime is 12378647. The reversal of 12378640 is 4687321.

It can be written as a sum of positive squares in 2 ways, for example, as 4892944 + 7485696 = 2212^2 + 2736^2 .

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 (12378647) 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, 77287 + ... + 77446.

Almost surely, 2^12378640 is an apocalyptic number.

12378640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12378640 is an abundant number, since it is smaller than the sum of its proper divisors (16401884).

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

12378640 is a wasteful number, since it uses less digits than its factorization.

12378640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 154746 (or 154740 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 12378640 is about 3518.3291489001. The cubic root of 12378640 is about 231.3259268577.

The spelling of 12378640 in words is "twelve million, three hundred seventy-eight thousand, six hundred forty".