13657123165561 has 4 divisors (see below), whose sum is σ = 13657283694324. Its totient is φ = 13656962636800.

The previous prime is 13657123165547. The next prime is 13657123165603. The reversal of 13657123165561 is 16556132175631.

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 13105268814400 + 551854351161 = 3620120^2 + 742869^2 .

It is a cyclic number.

It is not a de Polignac number, because 13657123165561 - 2⁴¹ = 11458099910009 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13657123165499 and 13657123165508.

It is not an unprimeable number, because it can be changed into a prime (13657123165531) 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, 80136700 + ... + 80306941.

It is an arithmetic number, because the mean of its divisors is an integer number (3414320923581).

Almost surely, 2^{13657123165561} is an apocalyptic number.

It is an amenable number.

13657123165561 is a deficient number, since it is larger than the sum of its proper divisors (160528763).

13657123165561 is an equidigital number, since it uses as much as digits as its factorization.

13657123165561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160528762.

The product of its digits is 3402000, while the sum is 52.

The spelling of 13657123165561 in words is "thirteen trillion, six hundred fifty-seven billion, one hundred twenty-three million, one hundred sixty-five thousand, five hundred sixty-one".