13809561 has 8 divisors (see below), whose sum is σ = 19381920. Its totient is φ = 8721792.

The previous prime is 13809557. The next prime is 13809569. The reversal of 13809561 is 16590831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 13809561 - 2² = 13809557 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (13809569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121080 + ... + 121193.

It is an arithmetic number, because the mean of its divisors is an integer number (2422740).

Almost surely, 2^13809561 is an apocalyptic number.

It is an amenable number.

13809561 is a deficient number, since it is larger than the sum of its proper divisors (5572359).

13809561 is a wasteful number, since it uses less digits than its factorization.

13809561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242295.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 13809561 is about 3716.1217687261. The cubic root of 13809561 is about 239.9164118632.

The spelling of 13809561 in words is "thirteen million, eight hundred nine thousand, five hundred sixty-one".