12640392 has 36 divisors (see below), whose sum is σ = 34316295. Its totient is φ = 4203408.

The previous prime is 12640373. The next prime is 12640393. The reversal of 12640392 is 29304621.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

12640392 is a `hidden beast` number, since 12 + 640 + 3 + 9 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 6320196 + 6320196 = 2514^2 + 2514^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=2514.

It is not an unprimeable number, because it can be changed into a prime (12640393) 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 8 ways as a sum of consecutive naturals, for example, 29959 + ... + 30377.

Almost surely, 2^12640392 is an apocalyptic number.

12640392 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

12640392 is an abundant number, since it is smaller than the sum of its proper divisors (21675903).

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

12640392 is an equidigital number, since it uses as much as digits as its factorization.

12640392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 850 (or 424 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 12640392 is about 3555.3328958060. The cubic root of 12640392 is about 232.9450649345.

Multiplying 12640392 by its product of nonzero digits (2592), we get a square (32763896064 = 181008²).

The spelling of 12640392 in words is "twelve million, six hundred forty thousand, three hundred ninety-two".