13659771809 has 4 divisors (see below), whose sum is σ = 13661122116. Its totient is φ = 13658421504.

The previous prime is 13659771787. The next prime is 13659771817. The reversal of 13659771809 is 90817795631.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4692250000 + 8967521809 = 68500^2 + 94697^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13659771809 is a prime.

It is a super-2 number, since 2×13659771809² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13659771889) 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, 659864 + ... + 680249.

It is an arithmetic number, because the mean of its divisors is an integer number (3415280529).

Almost surely, 2^13659771809 is an apocalyptic number.

It is an amenable number.

13659771809 is a deficient number, since it is larger than the sum of its proper divisors (1350307).

13659771809 is a wasteful number, since it uses less digits than its factorization.

13659771809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1350306.

The product of its (nonzero) digits is 2857680, while the sum is 56.

The spelling of 13659771809 in words is "thirteen billion, six hundred fifty-nine million, seven hundred seventy-one thousand, eight hundred nine".