13628661565 has 4 divisors (see below), whose sum is σ = 16354393884. Its totient is φ = 10902929248.

The previous prime is 13628661443. The next prime is 13628661589. The reversal of 13628661565 is 56516682631.

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 7533892804 + 6094768761 = 86798^2 + 78069^2 .

It is a cyclic number.

It is not a de Polignac number, because 13628661565 - 2¹³ = 13628653373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1362866152 + ... + 1362866161.

It is an arithmetic number, because the mean of its divisors is an integer number (4088598471).

Almost surely, 2^13628661565 is an apocalyptic number.

It is an amenable number.

13628661565 is a deficient number, since it is larger than the sum of its proper divisors (2725732319).

13628661565 is an equidigital number, since it uses as much as digits as its factorization.

13628661565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2725732318.

The product of its digits is 1555200, while the sum is 49.

The spelling of 13628661565 in words is "thirteen billion, six hundred twenty-eight million, six hundred sixty-one thousand, five hundred sixty-five".