13578640 has 20 divisors (see below), whose sum is σ = 31570524. Its totient is φ = 5431424.

The previous prime is 13578611. The next prime is 13578647. The reversal of 13578640 is 4687531.

It can be written as a sum of positive squares in 2 ways, for example, as 2396304 + 11182336 = 1548^2 + 3344^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 13578596 and 13578605.

It is not an unprimeable number, because it can be changed into a prime (13578647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 84787 + ... + 84946.

Almost surely, 2^13578640 is an apocalyptic number.

13578640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13578640 is an abundant number, since it is smaller than the sum of its proper divisors (17991884).

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

13578640 is a wasteful number, since it uses less digits than its factorization.

13578640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169746 (or 169740 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 13578640 is about 3684.9206232971. The cubic root of 13578640 is about 238.5716081949.

The spelling of 13578640 in words is "thirteen million, five hundred seventy-eight thousand, six hundred forty".