13985809 has 4 divisors (see below), whose sum is σ = 13995520. Its totient is φ = 13976100.

The previous prime is 13985761. The next prime is 13985813. The reversal of 13985809 is 90858931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 13985809 - 2²³ = 5597201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13985819) 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, 2217 + ... + 5734.

It is an arithmetic number, because the mean of its divisors is an integer number (3498880).

Almost surely, 2^13985809 is an apocalyptic number.

It is an amenable number.

13985809 is a deficient number, since it is larger than the sum of its proper divisors (9711).

13985809 is an equidigital number, since it uses as much as digits as its factorization.

13985809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9710.

The product of its (nonzero) digits is 77760, while the sum is 43.

The square root of 13985809 is about 3739.7605538323. The cubic root of 13985809 is about 240.9327647706.

The spelling of 13985809 in words is "thirteen million, nine hundred eighty-five thousand, eight hundred nine".