13578661 has 4 divisors (see below), whose sum is σ = 13801324. Its totient is φ = 13356000.

The previous prime is 13578659. The next prime is 13578701. The reversal of 13578661 is 16687531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16687531 = 7 ⋅2383933.

It can be written as a sum of positive squares in 2 ways, for example, as 690561 + 12888100 = 831^2 + 3590^2 .

It is a cyclic number.

It is not a de Polignac number, because 13578661 - 2¹ = 13578659 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13578661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13578601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111240 + ... + 111361.

It is an arithmetic number, because the mean of its divisors is an integer number (3450331).

Almost surely, 2^13578661 is an apocalyptic number.

It is an amenable number.

13578661 is a deficient number, since it is larger than the sum of its proper divisors (222663).

13578661 is an equidigital number, since it uses as much as digits as its factorization.

13578661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222662.

The product of its digits is 30240, while the sum is 37.

The square root of 13578661 is about 3684.9234727468. The cubic root of 13578661 is about 238.5717311822.

The spelling of 13578661 in words is "thirteen million, five hundred seventy-eight thousand, six hundred sixty-one".